Application Advice

pH Calibration of the Ultrameter 6PFCE: MyronLMeters.com

Posted by 23 Mar, 2014

Tweet  *Note: This procedure applies to the Ultrameter, PoolPro, TechPro, and D-6 Dialysate meter. IMPORTANT: Always “zero” your Ultrameter II with a pH 7 buffer solution before adjusting the gain with acid or base buffers, i.e., 4 and/or 10, etc. a. pH Zero Calibration (6PFCE) 1. Rinse sensor well and cell cup 3 times with […]

 

*Note: This procedure applies to the Ultrameter, PoolPro, TechPro, and D-6 Dialysate meter.

IMPORTANT: Always “zero” your Ultrameter II with a pH 7 buffer solution

before adjusting the gain with acid or base buffers, i.e., 4 and/or 10, etc.

a. pH Zero Calibration (6PFCE)

1. Rinse sensor well and cell cup 3 times with 7 buffer solution.

2. Refill both sensor well and cell cup with 7 buffer solution.

3. Press

pH

 

 

 

 

to verify the pH calibration. If the display shows 7.00, skip the pH

Zero Calibration and proceed to pH Gain Calibration.

4. Press

CAL key

 

 

 

 

 

to enter calibration mode. “CAL”, “BUFFER” and “7” will appear on the display.

display

 

 

 

 

 

 

 

Displayed value will be the uncalibrated sensor.

NOTES: If a wrong buffer is added (outside of 6-8 pH),“7” and “BUFFER

will flash, and the Ultrameter II will not adjust.

The uncalibrated pH value displayed in step 4 will assist in determining

the accuracy of the pH sensor. If the pH reading is above 8 with pH 7

buffer solution, the sensor well needs additional rinsing or the pH sensor

is defective and needs to be replaced.

5. Press

Up

 

 

 

 

or

Down

 

 

 

 

until the display reads 7.00.

NOTE: Attempted calibration of >1 pH point from factory calibration will

cause “FAC” to appear. This indicates the need for sensor replacement

or fresh buffer solution. The “FAC” internal electronic calibration is not intended to

replace calibration with pH buffers. It assumes an ideal pH sensor. Each “FAC”

indicates a factory setting for that calibration step (i.e., 7, acid, base).

You may press

CAL key

 

 

 

 

 

to accept the preset factory value, or you may

reduce your variation from factory setting by pressing

Up

 

 

 

 

or

Down

 

 

 

 

6. Press to accept the new value. The pH Zero Calibration

is now complete. You may continue with pH Gain Calibration or

exit by pressing any measurement key.

b. pH Gain Calibration (6PFCE)

IMPORTANT: Always calibrate or verify your Ultrameter II with a pH 7

buffer solution before adjusting the gain with acid or base buffers, i.e.,

4 and/or 10, etc. Either acid or base solution can be used for the 2nd

point “Gain” calibration and then the opposite for the 3rd point. The

display will verify that a buffer is in the sensor well by displaying either

Acd” or “bAS”.

1. The pH calibration mode is initiated by either completion of the

pH Zero Calibration, or verifying 7 buffer and pressing the

CAL key

 

 

 

 

 

key twice while in pH measurement mode.

2. At this point the “CAL”, “BUFFER” and “Acd” or “bAS

will be displayed (see Figures 7 and 8).

Capture

 

NOTE: If the “Acd” and “bAS” indicators are blinking, it indicates

an error and needs either an acid or base solution present in the sensor

well.

3. Rinse sensor well 3 times with acid or base buffer solution.

4. Refill sensor well again with same buffer solution.

5. Press

Up

 

 

 

 

or

Down

 

 

 

 

until the display agrees with the buffer value.

6. Press

CAL key

 

 

 

 

 

to accept the 2nd point of calibration. Now the

display indicates the next type of buffer to be used.

Single point Gain Calibration is complete. You may continue for the 3rd

point of Calibration (2nd Gain) or exit by pressing any measurement key.

Exiting causes the value accepted for the buffer to be used for both acid

and base measurements.

To continue with 3rd point calibration, use basic buffer if acidic buffer

was used in the 2nd point, or vice-versa. Again, match the display to the

known buffer value as in step 2 and continue with the following steps:

7. Repeat steps 3 through 6 using opposite buffer solution.

8. Press

CAL key

 

 

 

 

 

to accept 3rd point of calibration, which completes the Calibration procedure.

Fill sensor well with Sensor Storage Solution and replace protective cap.

You can find technical advice and videos, the calibration solutions you need, and reliable Myron L meters
at MyronLMeters.com
Categories : Application Advice, Care and Maintenance, Product Updates, Technical Tips

TDS Calibration on the Ultrameter II 6PIIFCe: MyronLMeters.com

Posted by 23 Mar, 2014

Tweet  *Note: This procedure applies to the Ultrameter, PoolPro, TechPro, and D-6 Dialysate meter. a. Fill and rinse the conductivity cell three times with a 442 standard solution. In this example, we’re using 442-3000. b. Refill conductivity cell with same standard solution you rinsed with. c. Press           then press   […]

 

*Note: This procedure applies to the Ultrameter, PoolPro, TechPro, and D-6 Dialysate meter.

a. Fill and rinse the conductivity cell three times with a 442 standard solution. In this example, we’re using 442-3000.

b. Refill conductivity cell with same standard solution you rinsed with.

c. Press

TDS

 

 

 

 

 

then press

 

.CAL key

 

 

 

 

The “CAL” icon will appear in the top center of the display. In this example, the reading shows 2988.

d. Press

Up

 

 

 

 

 

or

Down

 

 

 

 

 

to step the displayed value toward the standard’s value.

In this example, we’re pressing

 

Up

 

 

 

 

 

to go down from 2988 to 3000. You can also hold a key down to scroll rapidly.

e. Press

 

CAL key

 

 

 

 

 

once to confirm the new value and end the calibration.

You can find technical advice and videos, the calibration solutions you need, and reliable Myron L meters
at MyronLMeters.com
 
 

 

Categories : Application Advice, Care and Maintenance, Product Updates, Technical Tips

Conductivity Calibration on the Ultrameter II 6PIIFCe: MyronLMeters.com

Posted by 23 Mar, 2014

Tweet  *Note: This procedure applies to the Ultrameter, PoolPro, TechPro, and D-6 Dialysate meter. a.  Fill and rinse the conductivity cell three times with a KCL standard solution. In this example, we’re using KCL-7000. b. Refill conductivity cell with same standard solution you rinsed with. c. Press         then press .   […]

 

*Note: This procedure applies to the Ultrameter, PoolPro, TechPro, and D-6 Dialysate meter.

a.  Fill and rinse the conductivity cell three times with a KCL standard solution. In this example, we’re using KCL-7000.

b. Refill conductivity cell with same standard solution you rinsed with.

c. Press

COND

 

 

 

 

then press

CAL key

.

 

 

 

The “CAL” icon will appear on the display.

display

 

 

 

 

 

 

 

 

 

 

 

d. Press

Up

 

 

 

or

Down

 

 

 

 

to step the displayed value toward the standard’s value.

In this example, we’re pressing

Down

 

 

 

 

to go down from 7032 to 7000. You can also hold a key down to scroll rapidly.

e. Press

CAL key

 

 

 

 

 

once to confirm the new value and end the calibration.

You can find technical advice and videos, the calibration solutions you need, and reliable Myron L meters
at MyronLMeters.com
Categories : Application Advice, Care and Maintenance, Product Updates, Technical Tips

Questions About Inline Monitors, Controllers, Aquaswitches: MyronLMeters.com

Posted by 20 Mar, 2014

TweetMyronLMeters.com is the premier online distributor of Myron L Instruments. We make it easy to shop for your water quality testing instruments online. We understand that in order to make a buying decision you need more than just a recommendation or a product description. At MyronLMeters.com you will find detailed information about every product, including […]

MyronLMeters.com is the premier online distributor of Myron L Instruments. We make it easy to shop for your water quality testing instruments online. We understand that in order to make a buying decision you need more than just a recommendation or a product description. At MyronLMeters.com you will find detailed information about every product, including demo videos and customer reviews.

Since the 1960s, Myron L products have led the industry in high quality, simple to operate conductivity and pH instrumentation for municipal, commercial and industrial water quality control, chemical concentration testing and process control. Today, Myron L meters are more convenient than ever to research and buy right here at MyronLMeters.com. We provide the background, insight, product imagery and specifications you need to make the right choice–all in one convenient online store. Have questions that aren’t answered in our FAQ section or on the blog? Ask an expert by filling out a short form and we’ll respond with an answer within 24 hours. At MyronLMeters.com our mission is simple: Provide the best products with the best service, every day. We are proud to represent a quality product from a quality manufacturer!

My 750 Series II Monitor or Monitor/Controller display shows a 1, then a space, then a decimal point. What does this mean?
This is an over-range condition that can be fixed by performing an Electronic calibration of the circuit board. Please see directions in the Operations Manual or follow this brief review of Electronic Calibration. Hook up a Multi-Meter to the R+ and R- leads located at the top of the circuit board, switch the Multi-Meter to DC volts, push the Full Scale Push to Test button and read the DC voltage on the Multi-Meter. While pushing the Full Scale Push to Test button, adjust the CAL screw on the circuit board until the Multi-Meter reads 9.95-10.00 VDC. The display on the Myron L Monitor or Monitor/Controller should now read Full Scale.

How do I pick the correct range module for my Monitor or Monitor/Controller?
You must pick a range module that covers your 2/3 of your operating range. If you pick a range module that is too broad, then your accuracy will suffer or it will not show a number on the display. For example, if your operating range is 100-150 microsiemens, a range module of 0-200 microsiemens (-115) would be a good choice. A range module of 0-5,000 microsiemens (-123) would not be a good choice for this application.

Why does my displayed number fluctuate?
There is air or air bubbles around the sensor or the sensor is not properly installed. Tap on the sensor body to dislodge air bubbles or loosen securing nut to release trapped air. The sensor tip must be in the flow of water.

My device connected to the dry contact relay does not work and has no power. What do I do?
The Myron L dry contact relay does not draw power from the circuit board. You must supply the power to the relay to power your device.

Why is the display number on the Monitor or Monitor/Controller negative?
This is the offset that is being display and is caused when the sensor is not hooked up or is hooked up and sitting in air.

Why is the displayed number on the Monitor or Monitor/Controller half the reading than it should be?
This is caused when the 115/230 VAC switch is set to 230VAC when in fact it should be switched to 115 VAC.

Does the Aquaswitch I require any other device to help it switch banks?

Yes, the AquaSwitch I requires a Monitor/Controller in order to switch banks.

What is the recommended method to mount a Conductivity or Resistivity sensor?
The optimal method to mount the sensor is in the end of a tee with the water flowing directly into the tip of the sensor and flowing up and away at a 90 degree angle. Please see the 750 Series II Operations Manual for complete instructions.

I want to use my Monitor or Monitor/Controller for another application but the water quality is a totally different range. Can my existing unit be changed?
Our 750 Series II Conductivity/TDS and Resistivity Monitors and Monitor/Controllers can be “Re-Ranged” with a new range module to meet you changing needs. Simply un-plug the old range module and plug in the new range module into the circuit board. Refer to page 8 of the Operations Manual to see the Range Selection guide and to see if any minor modifications are necessary.

How can I tell what the model number of my Monitor or Monitor/Controller is?
The module number is circled on the transformer and printed on the back of the case.

Have other questions?  Try our literature database HERE, our video channel HERE, or use the handy Ask An Expert contact form at MyronLMeters.com.

Categories : Application Advice, Care and Maintenance, Product Updates, Technical Tips

Ultrameter: Measuring Conductivity, TDS and Resistivity: MyronLMeters.com

Posted by 1 Mar, 2014

TweetPlease note:  These procedures apply to Ultrameters, Pool Pros, Tech Pros, and D-4 and D-6 dialysate meters. Measuring Conductivity & TDS 1. Rinse cell cup 3 times with sample to be measured. (This conditions the temperature compensation network and prepares the cell.) 2. Refill cell cup with sample. 3. Press COND or TDS. 4. Take […]

Please note:  These procedures apply to Ultrameters, Pool Pros, Tech Pros, and D-4 and D-6 dialysate meters.

Measuring Conductivity & TDS

1. Rinse cell cup 3 times with sample to be measured. (This conditions

the temperature compensation network and prepares the cell.)

2. Refill cell cup with sample.

3. Press COND or TDS.

4. Take reading. A display of [- – – -] indicates an over range condition.

Measuring Resistivity

Resistivity is for low conductivity solutions. In a cell cup the value may drift from trace contaminants or absorption from atmospheric gasses, so measuring a flowing sample is recommended.

1. Ensure pH protective cap is secure to avoid contamination.

2. Hold instrument at 30° angle (cup sloping downward).

3. Let sample flow continuously into conductivity cell with no aeration.

4. Press RES key; use best reading.

NOTE: If reading is lower than 10 kilohms display will be dashes: [ – – – – ]. Use Conductivity.

If you have further questions, please watch our Ultrameter 6P product overview video here: http://blog.myronlmeters.com/ultrameter-ii-product-review/

 IV. AFTER USING THE ULTRAMETER II

Maintenance of the Conductivity Cell

Rinse out the cell cup with clean water. Do not scrub the cell. For oily films, squirt in a foaming non-abrasive cleaner and rinse. Even if a very active chemical discolors the electrodes, this does not affect the accuracy; leave it alone.

Myron L Meters is the premier internet retailer of Myron L meters, solutions, parts and accessories. Save 10% on the Ultrameter II 6PFCe when you order online at MyronLMeters.com.

Categories : Application Advice, Technical Tips

Conductivity Conversion to TDS in the Ultrameter: MyronLMeters.com

Posted by 1 Mar, 2014

TweetElectrical conductivity indicates solution concentration and ionization of the dissolved material. Since temperature greatly affects ionization, conductivity measurements are temperature dependent and are normally corrected to read what they would be at 25°C. A.           How It’s Done Once the effect of temperature is removed, the compensated conductivity is a function of the concentration (TDS). Temperature […]

Electrical conductivity indicates solution concentration and ionization of the dissolved material. Since temperature greatly affects ionization, conductivity measurements are temperature dependent and are normally corrected to read what they would be at 25°C.

A.           How It’s Done

Once the effect of temperature is removed, the compensated conductivity is a function of the concentration (TDS). Temperature compensation of the conductivity of a solution is performed automatically by the internal processor with data derived from chemical tables. Any dissolved salt at a known temperature has a known ratio of conductivity to concentration. Tables of conversion ratios referenced to 25°C have been published by chemists for decades.

B.           Solution Characteristics

Real world applications have to measure a wide range of materials and mixtures of electrolyte solutions. To address this problem, industrial users commonly use the characteristics of a standard material as a model for their solution, such as KCl, which is favored by chemists for its stability.

Users dealing with sea water, etc., use NaCl as the model for their concentration calculations. Users dealing with freshwater work with mixtures including sulfates, carbonates and chlorides, the three predominant components (anions) in freshwater that Myron L calls “Natural Water”. These are modeled in a mixture called “442™” which Myron L uses as a calibration standard, as it does standard KCl and NaCl solutions.

The Ultrameter II contains algorithms for these 3 most commonly referenced compounds. The solution type in use is displayed on the left. Besides KCl, NaCl, and 442, there is the User choice. The benefit of the User solution type is that one may enter the temperature compensation and TDS ratio by hand, greatly increasing accuracy of readings for a specific solution. That value remains a constant for all measurements and should be reset for different dilutions or temperatures.

C.           When does it make a lot of difference?

First, the accuracy of temperature compensation to 25°C determines the accuracy of any TDS conversion. Assume we have industrial process water to be pretreated by RO. Assume it is 45°C and reads 1500 µS uncompensated.

1.         If NaCl compensation is used, an instrument would report 1035 µS compensated, which corresponds to 510 ppm NaCl.

2.         If 442 compensation is used, an instrument would report 1024 µS compensated, which corresponds to 713 ppm 442.

The difference in values is 40%.

In spite of such large error, some users will continue to take data in the NaCl mode because their previous data gathering and process monitoring was done with an older NaCl referenced device.

Selecting the correct Solution Type on the Ultrameter II will allow the user to attain true TDS readings that correspond to evaporated weight.

If none of the 3 standard solutions apply, the User mode must be used.

TEMPERATURE COMPENSATION (Tempco) and TDS DERIVATION

The Ultrameter II contains internal algorithms for characteristics of the 3 most commonly referenced compounds. The solution type in use is displayed on the left. Besides KCl, NaCl, and 442, there is the User choice. The benefit of User mode is that one may enter the tempco and TDS conversion values of a unique solution via the keypad.

A. Conductivity Characteristics
When taking conductivity measurements, the Solution Selection determines the characteristic assumed as the instrument reports what a measured conductivity would be if it were at 25°C. The characteristic is represented by the tempco, expressed in %/°C. If a solution of 100 µS at 25°C increases to 122 µS at 35°C, then a 22% increase has occurred over this change of 10°C. The solution is then said to have a tempco of 2.2 %/°C. Tempco always varies among solutions because it is dependent on their individual ionization activity, temperature and concentration. This is why the Ultrameter II features mathematically generated models for known salt characteristics that also vary with concentration and temperature.

B. Finding the Tempco of an Unknown Solution

One may need to measure compensated conductivity of some solution unlike any of the 3 standard salts. In order to enter a custom fixed tempco for a limited measurement range, enter a specific value through the User function. The tempco can be determined by 2 different methods:

1. Heat or cool a sample of the solution to 25°C, and measure its conductivity. Heat or cool the solution to a typical temperature where it is normally measured. After selecting User function, set the tempco to 0 %/°C as in Disabling Temperature Compensation, pg. 15 (No compensation). Measure the new conductivity and the new temperature. Divide the % decrease or increase by the 25°C value. Divide that difference by the temperature difference.

2. Heat or cool a sample of the solution to 25°C, and measure its conductivity. Change the temperature to a typical measuring temperature. Set the tempco to an expected value as in User Programmable Temperature Compensation, pg. 15. See if the compensated value is the same as the 25°C value. If not, raise or lower the tempco and measure again until the 25°C value is read.

C. Finding the TDS Ratio of an Unknown Solution

Once the effect of temperature is removed, the compensated conductivity is a function of the concentration (TDS).

There is a ratio of TDS to compensated conductivity for any solution, which varies with concentration. The ratio is set during calibration in User mode as in User Programmable Conductivity to TDS Ratio, pg. 16.
A truly unknown solution has to have its TDS determined by evaporation and weighing. Then the solution whose TDS is now known can be measured for conductivity and the ratio calculated. Next time the same solution is to be measured, the ratio is known.

ph and ORP (6PFCE)

1. pH as an Indicator (6PFCE)

pH is the measurement of Acidity or Alkalinity of an aqueous solution. It is also stated as the Hydrogen Ion activity of a solution. pH measures the effective, not the total, acidity of a solution.
A 4% solution of acetic acid (pH 4, vinegar) can be quite palatable, but a 4% solution of sulfuric acid (pH 0) is a violent poison. pH provides the needed quantitative information by expressing the degree of activity of an acid or base. In a solution of one known component, pH will indicate concentration indirectly. However, very dilute solutions may be very slow reading, just because the very few ions take time to accumulate.

2. pH Units (6PFCE)

The acidity or alkalinity of a solution is a measurement of the relative availabilities of hydrogen (H+) and hydroxide (OH-) ions. An increase in (H+) ions increases acidity, while an increase in (OH-) ions increases alkalinity. The total concentration of ions is fixed as a characteristic of water, and balance would be 10-7 mol/liter (H+) and (OH-) ions in a neutral solution (where pH sensors give 0 voltage).
pH is defined as the negative logarithm of hydrogen ion concentration. Where (H+) concentration falls below 10-7, solutions are less acidic than neutral, and therefore are alkaline. A concentration of 10-9 mol/liter of (H+) would have 100 times less (H+) ions than (OH-) ions and be called an alkaline solution of pH 9.

3. The pH Sensor (6PFCE)

The active part of the pH sensor is a thin glass surface that is selectively receptive to hydrogen ions. Available hydrogen ions in a solution will accumulate on this surface and a charge will build up across the glass interface. The voltage can be measured with a very high impedance voltmeter circuit; the dilemma is how to connect the voltmeter to solution on each side.
The glass surface encloses a captured solution of potassium chloride holding an electrode of silver wire coated with silver chloride. This is the most inert connection possible from a metal to an electrolyte. It can
still produce an offset voltage, but using the same materials to connect to the solution on the other side of the membrane causes the 2 equal offsets to cancel.
The problem is, on the other side of the membrane is an unknown test solution, not potassium chloride. The outside electrode, also called the Reference Junction, is of the same construction with a porous plug in place of a glass barrier to allow the junction fluid to contact the test solution without significant migration of liquids through the plug material. Figure 33 shows a typical 2 component pair. Migration does occur, and this limits the lifetime of a pH junction from depletion of solution inside the reference junction or from contamination. The junction may be damaged if dried out because insoluble crystals may form in a layer, obstructing contact with test solutions.

Capture

Figure 33

 

Glass Surface

H+ ions

Junction plug
Platinum button

 

KCl solution

 

 

Glass

 

 

Electrode wires

 

 

 

4. The Myron L Integral pH Sensor (6PFCE)

The sensor in the Ultrameter II (see Figure 34) is a single construction in an easily replaceable package. The sensor body holds an oversize solution supply for long life. The reference junction “wick” is porous to provide a very stable, low permeable interface, and is located under the glass pH sensing electrode. This construction combines all the best features of any pH sensor known.

5. Sources of Error (6PFCE)

The most common sensor problem will be a clogged junction because a sensor was allowed to dry out. The symptom is a drift in the “zero” setting at 7 pH. This is why the Ultrameter II 6PFCE does not allow more than 1 pH unit of offset during calibration. At that point the junction is unreliable.

b. Sensitivity Problems

Sensitivity is the receptiveness of the glass surface. A film on the surface can diminish sensitivity and cause a long response time.

c. Temperature Compensation

pH sensor glass changes its sensitivity slightly with temperature, so the further from pH 7 one is, the more effect will be seen. A pH of 11 at 40°C would be off by 0.2 units. The Ultrameter II 6PFCE senses the sensor well temperature and compensates the reading.

B. ORP/Oxidation-Reduction Potential/REDOX (6PFCE)

1. ORP as an Indicator (6PFCE)

ORP is the measurement of the ratio of oxidizing activity to reducing activity in a solution. It is the potential of a solution to give up electrons (oxidize other things) or gain electrons (reduce).
Like acidity and alkalinity, the increase of one is at the expense of the other, so a single voltage is called the Oxidation-Reduction Potential, with a positive voltage showing, a solution wants to steal electrons (oxidizing agent). For instance, chlorinated water will show a positive ORP value.

2. ORP Units (6PFCE)

ORP is measured in millivolts, with no correction for solution temperature. Like pH, it is not a measurement of concentration directly, but of activity level. In a solution of only one active component, ORP indicates concentration. Also, as with pH, a very dilute solution will take time to accumulate a readable charge.

3. The ORP Sensor (6PFCE)
An ORP sensor uses a small platinum surface to accumulate charge without reacting chemically. That charge is measured relative to the solution, so the solution “ground” voltage comes from a reference junction – same as the pH sensor uses.

4. The Myron L ORP Sensor (6PFCE)

Figure 34, pg. 45, shows the platinum button in a glass sleeve. The same reference is used for both the pH and the ORP sensors. Both pH and ORP will indicate 0 for a neutral solution. Calibration at zero compensates for error in the reference junction. A zero calibration solution for ORP is not practical, so the Ultrameter II 6PFCE uses the offset value determined during calibration to 7 in pH calibration (pH 7 = 0 mV). Sensitivity of the ORP surface is fixed, so there is no gain adjustment either.

5. Sources of Error (6PFCE)

The basics are presented in pH and ORP, pg. 44, because sources of error are much the same as for pH. The junction side is the same, and though the platinum surface will not break like the glass pH surface, its protective glass sleeve can be broken. A surface film will slow the response time and diminish sensitivity. It can be cleaned off with detergent or acid, as with the pH glass.

C. Free Chlorine

1. Free Chlorine as an Indicator of Sanitizing Strength Chlorine, which kills bacteria by way of its power as an oxidizing agent, is the most popular germicide used in water treatment. Chlorine is not only used as a primary disinfectant, but also to establish a sufficient residual level of Free Available Chlorine (FAC) for ongoing disinfection.

FAC is the chlorine that remains after a certain amount is consumed by killing bacteria or reacting with other organic (ammonia, fecal matter) or inorganic (metals, dissolved CO2, Carbonates, etc) chemicals in solution. Measuring the amount of residual free chlorine in treated water is a well accepted method for determining its effectiveness in microbial control.

The Myron L  FCE method for measuring residual disinfecting power is based on ORP, the specific chemical attribute of chlorine (and other oxidizing germicides) that kills bacteria and microbes.

2. FCE Free Chlorine Units

The 6PIIFCE is the first handheld device to detect free chlorine directly, by measuring ORP. The ORP value is converted to a concentration reading (ppm) using a conversion table developed by Myron L Company through a series of experiments that precisely controlled chlorine levels and excluded interferants.

Other test methods typically rely on the user visually or digitally interpreting a color change resulting from an added reagent-dye. The reagent used radically alters the sample’s pH and converts the various chlorine species present into a single, easily measured species. This ignores the effect of changing pH on free chlorine effectiveness and disregards the fact that some chlorine species are better or worse sanitizers than others.

The Myron L 6PIIFCE avoids these pitfalls. The chemistry of the test sample is left unchanged from the source water. It accounts for the effect of pH on chlorine effectiveness by including pH in its calculation. For these reasons, the Ultrameter II’s FCE feature provides the best reading-to-reading picture of the rise and fall in sanitizing effectivity of free available chlorine.

The 6PIIFCE also avoids a common undesirable characteristic of other ORP-based methods by including a unique Predictive ORP value in its FCE calculation. This feature, based on a proprietary model for ORP sensor behavior, calculates a final stabilized ORP value in 1 to 2 minutes rather than the 10 to 15 minutes or more that is typically required for an ORP measurement.

The Myron L Ultrameter II 6PFCe is available at MyronLMeters.com, the premier internet retailer of Myron L products. Save 10% on the Myron L Ultrameter II6 PFCe when you order online here: http://www.myronlmeters.com/Myron-L-6P-Ultrameter-II-Multiparameter-Meter-p/dh-umii-6pii.htm

 

Categories : Application Advice, Technical Tips

Water Quality in Hydroponics Applications: MyronLMeters.com

Posted by 7 Jan, 2014

TweetWHAT IS HYDROPONICS? “A technique of growing plants in nutrient solution”. Hydroponics literally means water-working or water-activation. It is a cultivation technique for growing plants in highly oxygenated, nutrient enriched water, rather than soil. The nutrient solution and its management are the cornerstone for a successful hydroponics system. The function of a hydroponics nutrient solution […]

WHAT IS HYDROPONICS?
“A technique of growing plants in nutrient solution”. Hydroponics literally means water-working or water-activation. It is a cultivation technique for growing plants in highly oxygenated, nutrient enriched water, rather than soil.

The nutrient solution and its management are the cornerstone for a successful hydroponics system. The function of a hydroponics nutrient solution is to supply the plant roots with water, oxygen and essential mineral elements in soluble form.

In soil, biological decomposition breaks down organic matter into basic nutrients that plants feed on. Water dissolves these nutrients which allows uptake by the roots. For a plant to receive a well balanced diet, everything in the soil must be in perfect balance.

Depending on the product, there are approximately seventeen (17) required elements for proper growth. For growth of higher plants, nine of these elements (macro nutrients) carbons, hydrogen, oxygen, sulfur, phosphorus, calcium, magnesium, potassium, and nitrogen are required in relatively large amounts. The remaining eight elements (micro-nutrients or trace elements) iron, zinc, copper, manganese, boron, chlorine, cobalt, and molybdenum are needed in only minute amounts.

To support a plant in a system, an insert medium like fiber or leca, may be used to anchor the roots. These mediums are designed to be very porous for excellent retention of air and water for healthy plants-roots to breathe! With the proper light exposure, nutrients, pH and EC/TDS measurements, plants will grow many times faster, bigger and healthier.

WHAT IS pH? WHY IS IT IMPORTANT?
pH, means “potential hydrogen” ion concentration (commonly referred to as acidity or alkalinity) in a particular medium, such as water, soil, etc. All elements have a specific solubility pH range. This means that mineral elements can become more available for plant uptake within certain pH ranges. The scale of pH is 0 to 14, 14 is the highest for alkalinity, 7 is neutral, and 0 is the highest acidity. It is well documented that growing media pH is critical to successful plant growth. This is especially true for soilless mixes and hydroponics.

Extreme pH conditions such as very low pH (below pH 4.5) and very high pH (above pH 9) can cause damage to plant roots and limit or kill production.

WHAT IS ELECTRICAL CONDUCTIVITY (EC) OR TOTAL DISSOLVED SOLIDS (TDS)? WHY IS IT IMPORTANT?
EC [displayed in either microsiemens (μS) or micromhos (μM)] is the measurement of the nutrient solutions ability to conduct an electrical current. In hydroponics the conductivity (EC) is most commonly expressed in an equivalent Total Dissolved Solids (TDS) value. The unit of measurement for TDS is parts per million (ppm). Pure water (deionized water) is actually an insulator — it does not conduct electricity. It is the conductive substances (or ionized salts) dissolved in the water that determine how conductive the solution is. With few exceptions, when there is a greater concentration of nutrients, the electrical current will flow faster, and when there is a lower concentration, the current will flow slower.

This is because the quantity of dissolved solids in the nutrient solution is directly proportional to the conductivity. Thus, by measuring the EC, one can determine how strong or weak the concentration of the nutrient solution is.

HOW IS EC CONVERTED TO PPM OF TDS?
Myron L meters use a complex equation that exactly matches the true TDS of the solution being tested. While other instrument manufacturers use a “fixed” factor (easier and less costly to manufacture) to “estimate” the TDS from electrical conductivity. As you can see in the following examples a fixed factor of, for example .5 is far off the mark.

solution table

 

 

 

 

 

TEMPERATURE COMPENSATION (TC), WHY IS IT IMPORTANT?
Without Temperature Compensation (TC), instrumentation measuring waters/nutrients would be indicating different values at differing temperatures. TC standardizes the readings at the international standard of 25°C / 77°F. With proper TC all readings will be repeatable at differing temperatures and may be correlated. All Myron L meters use advanced TC circuitry and equations to give you the best TC correction available.

CALIBRATION STANDARD SOLUTIONS
Clearly the “BEST” choice when calibrating instrumentation for controlling water and nutrients in Hydroponics, Greenhouses and Agricultural applications is the “442™” natural water standard.

This standard developed over 40 years ago closely matches the composition of natural water. The “442” refers to the combination of salts with deionized water to make the standard: 40% sodium sulfate, 40% sodium bicarbonate, and 20% sodium chloride. Since its development, it has become the world’s most accepted natural water standard. All HYDROPONICS Instruments from the Myron L Company are calibrated using this standard.

For truly accurate and repeatable readings for your Hydroponic applications, use Myron L meters and “442” Standard Solutions.

All instrumentation, pH buffers and EC/TDS standards are available HERE at MyronLMeters.com.

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Categories : Application Advice, Technical Tips

Horticulture Applications: MyronLMeters.com

Posted by 13 Nov, 2013

Tweet                    WHY ARE TESTS SO IMPORTANT? Modern growing practices include scientific evaluations of soil, water, fertilizers, diseases, etc. While some tests are best performed by a laboratory, others can be easily conducted on location, saving time and money. Three tests in particular, EC, pH, and ALKALINITY, […]

The Myron L Ag-6/pH

 

 

 

 

 

 

 

 

 

 

WHY ARE TESTS SO IMPORTANT?

Modern growing practices include scientific evaluations of soil, water, fertilizers, diseases, etc. While some tests are best performed by a laboratory, others can be easily conducted on location, saving time and money. Three tests in particular, EC, pH, and ALKALINITY, can reveal valuable information about water quality, soil salinity, and fertilizer concentration. Our portable AGRI-METERS™ provide you with a simple, fast, and accurate means of testing these parameters.

WHAT IS ELECTRICAL CONDUCTIVITY (EC)?

EC is the measurement of a solution’s ability to conduct an electrical current. For horticultural applications, the unit of measure is often expressed as millimhos. Absolutely pure water is actually a poor electrical conductor. It is the substances (or electrolytes) dissolved in the water which determine how conductive the solution will be.

Therefore, EC can be an excellent indicator of:

1. Water quality

2. Soil salinity

3. Fertilizer concentration

EC AND WATER QUALITY

The quality of irrigation water is one of the most critical factors influencing your growing operation. It is important to have a complete water analysis performed on a regular basis. Environmental conditions such as drought, changing seasons, heavy rainfall, etc., can cause the concentrations of dissolved salts in your water to vary significantly. These dissolved salts (i.e. calcium, sodium, etc.) can directly affect your plants’ health and, over time, render even the best soil useless.

You can monitor your overall water quality by testing its electrical conductivity with an AGRI-METER™. The higher the EC, the more salts are dissolved in your water. By comparing your EC with previous readings, you can tell if any dramatic changes have occurred. Nutrient deficiencies are possible when water is too pure (low EC) or if the relative concentrations of some nutrients are unbalanced (i.e. calcium/magnesium). On the other hand, nutrient toxicities or osmotic interferences can also be traced to water quality. Water EC of even one millimho or below can cause problems. High EC readings of more than two millimhos can suggest serious problems, and special cultural procedures may be required.

EC AND SOIL SALINITY

“Water, water, everywhere, but not a drop to drink” is an old saying that applies to your plants when the soil salinity becomes too high. Salts from irrigation water and fertilizers tend to accumulate in your soil or growing media. High soil salinity disrupts the normal osmotic balance in plant roots. In severe cases a plant will become dehydrated even when the soil is wet. Symptoms of high soil salinity include: leaf chlorosis and necrosis, leaf drop, root death, nutrient deficiency symptoms, and wilting. All too often these symptoms are not recognized as being caused by soluble salts in the growing media. Sampling your soil and testing the EC of an extract can reveal important information about a soil’s suitability and your crop’s health.

Samples should be representative of different depths and locations. An easy-to-perform extract method is available with a Soil Test Kit. A 2:1 or 5:1 water-to-soil ratio is made using the small vials provided. Soil test labs often use a method that calls for testing the EC of an extract from a thicker slurry. Therefore, you may see higher soil EC readings from a lab. It is important to standardize your sampling, extract, and testing methods. This will keep the difference between lab and field testing to a predictable factor.

EC AND FERTILIZER CONCENTRATION

You know how important fertilizer is to your plants, but do you know how accurate your fertilizer dosage is? Relying on traditional proportional methods is risky to plants and can waste expensive fertilizer. Improperly mixed fertilizer or a malfunctioning injector can lead to less than optimal results or even a disastrous loss of crops. Many fertilizer companies now recommend using a simple EC test to verify correct fertilizer concentrations. Many growers check their fertilizer injectors on a weekly basis, or they use a continuous EC monitor.

Fertilizer companies and suppliers often can provide a chart relating EC to parts per million concentrations of their various fertilizers. If one is not available for the fertilizer you use, carefully make some stock solutions at commonly used strengths and test their EC. This will give you a data base for future reference.

To test the EC of fertilizer solutions:

  1. Test and record the EC of the water to be mixed with the fertilizer.
  2. Test the conductivity of the fertilizer and water mixture.
  3. Subtract the water conductivity determined in #1 above.
  4. The resulting figure is an accurate indication of how much fertilizer is present (a higher conductivity means more fertilizer).

Important note: Interpretation of results differs from formula to formula and even among manufacturers of the same formula. Obtain the proper EC charts from the fertilizer company.

Myron L Meters sells both portable and inline instrumentation to make your fertilizer monitoring easy. Myron L AGRI-METERS™, AG-5 and AG6/PH, TH1, waterproof TECHPRO II™ models TP1, TPH1 and TH1, and waterproof ULTRAMETER II™ models 4P and 6PFCEare handheld instruments which make fertilizer testing as simple as filling a cup and pushing a button.

The Myron L 750 Series II™ EC Monitor/controllers can be used to continuously monitor your fertilizer concentration. Their “alarm” relay circuit acts as a safeguard in a fertilizer injection system or even as the main controller for your injector. A 0-10 VDC output for chart recorders or PLC (SCADA) input is standard on all monitor/controller models.

IMPORTANCE OF pH

pH, the measure of acidity or basicity, should be included in any soil or water test. It is well documented that growing media pH is critical to successful plant growth. This is especially true for new soilless mixes and hydroponics. pH affects the roots’ ability to absorb many plant nutrients. Examples include iron and manganese, which are insoluble at high pHs and toxic at low pHs. pH also directly affects the health of necessary micro-organisms in soil.

The effectiveness of pesticides and growth regulators can be severely limited by spray water pH that is either too low or too high.

ALKALINITY

It is important to note that testing the pH of irrigation water reveals only part of the story. Testing water alkalinity (bicarbonates and carbonates) is much more important than generally recognized. Alkalinity dictates how much influence the water’s pH will have on your soil and nutrient availability. In addition, alkalinity has a very great effect on the ease or difficulty of reducing the pH of water.

 

 

Categories : Application Advice, Case Studies & Application Stories

Myron L Meters for Hydroponics: MyronLMeters.com

Posted by 5 Sep, 2013

TweetFeatures • Handheld meters measure TDS and/or pH • Monitor measures TDS • All instruments are easy to operate and calibrate • High degree of accuracy • Immediate results • Kit comes with solutions required to calibrate • Temperature compensated readings TDS Monitoring The nutrient solution and its management are the foundation of a successful […]

Features

• Handheld meters measure TDS and/or pH
• Monitor measures TDS
• All instruments are easy to operate and calibrate
• High degree of accuracy
• Immediate results
• Kit comes with solutions required to calibrate
• Temperature compensated readings

TDS Monitoring

The nutrient solution and its management are the foundation of a successful hydroponics system. The function of a hydroponics nutrient solution is to supply the plant roots with water, oxygen and essential mineral elements in soluble form.

A test of the Total Dissolved Solids (TDS) using the DS Meter or pDS Meter or continuous monitoring with the HYDRO-STIK gives the grower accurate measurements of the concentration of nutrients in solution. If the concentration drops below the optimum level required to sustain and grow the plants, add more nutrient- rich solution until the desired concentration level is achieved. This prevents haphazard dosing and wasted solution, which minimizes costs to the grower.

pH Monitoring

pH of the nutrient solution is also critical to successful plant growth. All elements have a specific solubility pH range. This means that mineral elements dissolve and can become more concentrated in solution within certain pH ranges. Roots absorb only the dissolved nutrients, so this is critical to plant growth.
The TH1H and the pDS Meter quickly and easily measure pH.

Monitoring the addition of a pH balancing solution with the proper meter lets the grower precisely adjust the pH level.

Beyond affecting nutrient availability, extremely low or high pH can even damage or kill plants.

All Myron L TDS and pH meters give lab-accurate results in the field.

All Myron L meters use advanced Temperature Compensation (TC) circuitry and equations to give you the best TC correction available.

Ultrapen PT2 pH and Temperature Pen

Ultrapen PT2 pH and Temperature Pen

Ultrapen PT1 TDS Pen

Ultrapen PT1 TDS Pen

T6/pH TDS and pH Meter

T6/pH TDS and pH Meter

Techpro II - TPH1 TDS, pH, Conductivity, Temperature

Techpro II – TPH1 TDS, pH, Conductivity, Temperature

PSTK Soil Test Kit

PSTK Soil Test Kit

 

 

Categories : Application Advice

Using LSI to preserve an Arizona treatment plant’s distribution systems

Posted by 16 Aug, 2013

Tweet                    The first thing anyone who manages water and wastewater learns is that water is the universal solvent. Because of the unique properties of that dihydrogen monoxide molecule, owing to the extreme electronegativity of the oxygen atom, water is highly polarized and dissolves almost everything with […]

Myron L Ultrameter II 6P

 

 

 

 

 

 

 

 

 

 

The first thing anyone who manages water and wastewater learns is that water is the universal solvent. Because of the unique properties of that dihydrogen monoxide molecule, owing to the extreme electronegativity of the oxygen atom, water is highly polarized and dissolves almost everything with which it comes into contact. This fact is important when one has to maintain equipment and structures that process and distribute water because what the water has dissolved in it can cause it to be corrosive or scaling. What water generally has dissolved in it is at least some carbon dioxide and some calcium carbonate.

Carbon dioxide is ubiquitous and dissolves at the surface of the water, forming carbonic acid in solution. Calcium carbonate, dissolved by the carbonic acid, is globally present in rock formations (limestone), as well as in the physiological structures of organisms (particularly oceanic organisms) that excrete it. Calcium carbonate in its various forms is also used to buffer pH and stabilize solution in process control. Managing the calcium carbonate equilibrium becomes critical to managing any water and wastewater treatment process.

Too little calcium carbonate yields water that is not saturated and may cause corrosion and deteriorate equipment and structures. A supersaturated solution will likely precipitate calcium carbonate, causing scale, reducing efficiency and eventually leading to system failure.

LSI in AZ

One method for analyzing and managing corrosion and scale deposition of water is to use the Langelier Saturation Index (LSI). In Scottsdale, Ariz., Gary Lyons is managing LSI at his water treatment facility using the Myron L Ultrameter II 6P.

His drinking water treatment plant takes 70 million gal per day (mgd) of water from the Central Arizona Project canal and treats it for residential and commercial use. Within the 143-acre campus, the plant processes 20 mgd to of wastewater from the city of Scottsdale collection system using microfiltration and reverse osmosis (RO). Water coming from the RO treatment process is acidic around pH 5.5. It is then moved to decarbonation towers and lime is added to bring the LSI value close to zero. The water reclamation plant features 8 mgd of storage capacity. Recycled water treated by the plant is used for the irrigation of 20 Scottsdale golf courses.

There is great concern about how the water balance will affect this distribution system over time, especially due to higher total dissolved solids values. Plant technicians compute LSI values in the field with the 6Psi hand-held to determine what adjustments should be made and how in real time. The LSI calculator allows them to perform what-if scenarios on changes in pH, alkalinity, hardness and temperature. They are able to measure the effects of changes immediately as well in the facility and at distribution points.

Hardness and alkalinity are variables in the LSI calculation because they account for the availability of calcium in various forms in the water. Variables such as temperature and pH contribute to the likelihood of the formation of calcium carbonate.

The version of the LSI calculation used by the 6Psi LSI calculator is:

LSI = pH + TF + CF + AF – 12.1

In this calculation, pH = the measured value of pH in pH units; TF = 0.0117 x temperature – 0.4116; CF = 0.4341 x ln(Hrd) – 0.3926; and AF = 0.4341 x ln(AL) – 0.0074.

The first thing anyone who manages water and wastewater learns is that water is the universal solvent. Because of the unique properties of that dihydrogen monoxide molecule, owing to the extreme electronegativity of the oxygen atom, water is highly polarized and dissolves almost everything with which it comes into contact. This fact is important when one has to maintain equipment and structures that process and distribute water because what the water has dissolved in it can cause it to be corrosive or scaling. What water generally has dissolved in it is at least some carbon dioxide and some calcium carbonate.

Carbon dioxide is ubiquitous and dissolves at the surface of the water, forming carbonic acid in solution. Calcium carbonate, dissolved by the carbonic acid, is globally present in rock formations (limestone), as well as in the physiological structures of organisms (particularly oceanic organisms) that excrete it. Calcium carbonate in its various forms is also used to buffer pH and stabilize solution in process control. Managing the calcium carbonate equilibrium becomes critical to managing any water and wastewater treatment process.

Too little calcium carbonate yields water that is not saturated and may cause corrosion and deteriorate equipment and structures. A supersaturated solution will likely precipitate calcium carbonate, causing scale, reducing efficiency and eventually leading to system failure.

Indicator Analysis

LSI has been useful as a scaling/corrosion indicator in municipal water treatment for more than 70 years. The original Langelier Saturation (or Stability) Index calculation was developed by Dr. Wilfred Langelier in 1936 to be used as a tool to develop strategies to counteract corrosion of plumbing in municipal water distribution systems. It is a statement about the change in pH required to bring the calcium carbonate in water to equilibrium. LSI is a measure of the disparity between the pH of the system and the pH at which the system is saturated with calcium carbonate: LSI = pH – pH of saturation.

As such, the LSI indicates the change in pH required to bring water to equilibrium. If the LSI is +1, then the pH needs to be lowered by one unit to bring the water to equilibrium. If the LSI is -1, the pH needs to be raised by one unit to bring the water to equilibrium.

A positive saturation index means that the pH of the water is above equilibrium. The water is scaling because as pH increases, total alkalinity concentration increases. This is due to an increase in the carbonate ion, which bonds with calcium ions present in solution to form calcium carbonate (reference the carbonic acid equilibrium, in which hydrogen ions bond with carbonate ions to form bicarbonate and hydrogen ions bond with bicarbonate to form carbonic acid). Thus, any positive value for LSI is scaling.

If the pH is less than the pH of saturation, the index will be negative, which is corrosive. This means that the water is more acidic than it would be at equilibrium. There are less carbonate ions present, according to the carbonic acid equilibrium. The water will be aggressive because it has room for more ions in solution. Thus, any negative value for LSI indicates that the water may tend to be corrosive.

The use of LSI as an indicator is well documented and time-tested. Managing water balance through LSI analysis will prevent loss of efficiency and failure of equipment and structures, saving time and money.

Myron L Meters is the premier online internet retailer of the Myron L Ultrameter II 6P.  Find out more about the Ultrameter II 6P here:

https://www.myronlmeters.com/Myron-L-6P-Ultrameter-II-Multiparameter-Meter-p/dh-umii-6pii.htm

Categories : Application Advice, Case Studies & Application Stories, Technical Tips