Conductivity Standard Solutions

Sensorex offers a wide range of Mixed Salt and Single Salt Conductivity Standards.  Our standards are prepared to NIST (National Institute of Standards and Technology) primary solutions standards.  Both Mixed Salts and Single Salt solutions are available.  A NIST certificate is available for a nominal charge.

Conductivity cells and meters must be calibrated together. Industrial customers will often calibrate 3 to 5 times per year.  Cells used in analytical laboratories are calibrated with greater frequency.

Solutions are supplied in quart bottles (946 ml) and are ready for immediate use.  Both the TDS and the conductivity values are listed on the label.   Shelf life is guaranteed for a year, and each solution is supplied with an MSDS sheet.  Custom standards with special conductivity values or special packaging requirements are available on request.

For a single point calibration, select the one solution that approximates the expected conductivity or ppm level of total salts.   Multipoint calibrations can be accomplished using 2 or more standards.

Aqueous solutions with a single Salt, will exhibit a specific relationship of conductivity vs. ppm concentration.  Each mineral salt has it's own unique curve.  The curve for potassium chloride, for example, is different than sodium carbonate.  These characteristics makes it difficult to accurately measure a sample containing a mixture of different salts. 

Sensorex Mixed Salt standards provide a useful, and practical solution to this phenomenon.  Mixed Salt standards are the most frequently used in the field to sample naturally occurring water sources, boiler feed water or cooling tower water. 

A typical river water, well water or lake water sample will contain a mixture of several different salts.  Sensorex Mixed Salt standards simulate a "Natural" mixture of common salt compounds found in these sources.  Sodium sulfate, sodium bicarbonate and sodium chloride salts are blended to provide a representative value.  Mixed salt standards are useful laso for calibrating cells for boiler feed water and cooling towers.  Mixed Salt standards will likely be the best choice for your cell calibration, except as noted below.