Instruction Manual

IX. GLOSSARY
442™ An Internationally recognized “natural water”
standard developed by the Myron L Company in
1964.
Algorithm A procedure for solving a mathematical
problem. See Addendum, Temperature
Compensation and TDS Derivation.
Anions Negatively charged ions
DVM Digital Volt Meter
Hysteresis Dead Band — related to alarm set
point. The amount of delay or overlap
between change from high to low or low
to high.
LCD Liquid Crystal Display
KCl Potassium Chloride — used as a
standard for many applications.
Normally, micromhos or microsiemens
are the units of measure.
NaCl Sodium Chloride — used as a
standard for sea water and other
applications.
NIST National Institute Standards & Testing
PLC Programmable Logic Controller
PPM Parts Per Million — common units of measure
for TDS.
PPT Parts Per Thousand — common units of
measure for TDS.
SCADA Supervisory Control And Data Acquisition
Tempco (TC) Temperature Compensation — See Addendum,
Temperature Compensation.
TDS Total Dissolved Solids or the Total Conductive
Ions in a solution — normally displayed as ppm
or ppt. See Addendum, Conductivity
Conversion to TDS.
Tweaker A screwdriver specially designed for adjusting
electrical calibration controls.
µM or µS Micromho or microsiemen — common unit of
measure for conductivity.
Meg or ohm Megohm — common unit of measurement for
resistivity.
USP25 United States Pharmaceutical regulation,
revision number 25. In part, requires
Conductivity/TDS, resistivity or pH
measurements be taken, recorded and/or
systems controlled using equipment without
temperature compensation. Requires a
separate temperature measuring device
(temperature measurements may be part of
Cond/TDS, Resistivity or pH device but must
not correct measurements for temperature
errors).
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