All Myron L® handheld instruments are
factory calibrated with NIST traceable Standard Solutions
having specific conductivity/ppm values. Myron L® Company
Standard Solutions are made under strictly controlled
conditions using reagent grade salts. These salts are mixed
with deionized water having a resistivity of at least 5
Myron L® Company Standard
Solutions have an accuracy of +1% based on values published
in the International Critical Tables and traceable to the
National Institute of Standards and Technology.
The conductivity Standard
Solutions and pH Buffers listed to the right are used for
factory calibration. Regular use of these solutions is
recommended to ensure specified instrument accuracy.
Frequency of conductivity recalibration depends upon use,
but once every month should be sufficient for an instrument
used daily. pH models, depending upon use, should be
recalibrated with pH 7 Buffer every 1-2 weeks, and checked
with pH 4 and/or 10 Buffers at similar intervals. pH Sensor
Storage Solution is recommended for keeping the pH sensor
hydrated. Myron L® solutions are available in quart/1 ltr.,
gallon/3,8 ltr. and 2 oz./59 ml plastic bottles, ready to
use. (Custom value standards only offered in gallon/3,8 ltr.
For information on ORP Conditioner and Calibration solutions, call the Myron L® Company.
Refer to TDS/Conductivity Equivalents chart for actual calibration point values.
RE-10 Range Extenders are usually calibrated with either 442-15,000 or 442-30,000 Standard Solution.
Conductivity instruments are a convenient way to determine the parts per million of total dissolved solids (ppm/TDS) in boilers, cooling towers, reverse osmosis systems, etc. Although the International Unit (Sl) of measuring conductivity is the microsiemens/ cm (also known as micromhos/cm), a direct reading in ppm/TDS is sometimes preferred.
conductivity instruments and monitor/ controllers are calibrated to read in ppm/442,
ppm/ NaCI, or microsiemens. All three values are listed on our Standard
Solutions. The relationship among these standards can be seen in the table and
graphs that follow.
442 Natural Water™ Standard Solution
is used in calibrating many Myron L® Instruments. It is the best choice when
measuring boiler and cooling water samples, city water supply, lakes, wells,
etc. "442" refers to the combination of salts mixed with deionized water to
comprise this standard: 40% sodium sulfate, 40% sodium bicarbonate, 20% sodium
chloride. A combination of standard salts is necessary since natural water salt
type and concentration can vary greatly by location. After much research, the
442 Standard was developed by the Myron L® Company more than 40 years ago. It
remains the world's most accepted standard.
NaCl Standard Solution is offered to
calibrate instruments that measure any sample that is predominately NaCI (sodium
chloride), such as sea water, brackish water, etc. As can be seen in the graph
at right, 1000 ppm of NaCI has a conductivity of 2000 micromhos. Note how this
1:2 relationship is continuously variable throughout the curve and decreases as
ppm NaCI increases.
KCl Standard Solution is used to
calibrate conductivity instruments that read directly in microsiemens (micromhos)
or millisiemens (1000 microsiemens). KCI (potassium chloride) is a very stable
salt and is an international calibration standard for conductivity measurement.
pH Buffer Solutions 4, 7 and 10 are
mold inhibited and accurate to within + 0.01 pH units @ 25°C. Myron L® Buffers
are traceable to NIST certified pH references and are color-coded for instant
Reagents, buffers and calibration solutions for alkalinity, hardness and LSI titrations, as well as ORP sensor conditioner and calibration solutions are also available. Contact the Myron L® Company for more information.
MSDS are available from the Myron L® website here: