Water conductivity meter

In order to test the conductivity of nominally deionized water (e.g. the TF cooling water), a water conductivity meter was purchased. The lowest calibration range of the meter is rated as "0-1.99μS," and the calibration guidelines suggest accepting a calibration value within 20% of the rated conductivity of each calibration fluid. This suggests the meter is reliable to at least ±0.4μS precision in the lowest range. For comparison, water from the hallway water cooler was measured at 280μS, and from the building deionized water hose was measured at 2μS.

Operation

Fig. 1: Fisher Scientific water conductivity meter.

When turned on, the meter automatically starts in conductivity mode, and automatically resets its dynamic range to the appropriate scale. If it has been left out, the probe should be rinsed with clean water before use to minimize any contamination. The tip of the probe should be fully immersed and stirred gently to ensure a homogeneous measurement, avoiding spuriously high readings due to any local contamination on the probe.

Modes

The three-letter mode symbols appear above the measurement value on the LCD screen. The conductivity meter should be used in "CON" (conductivity) mode; if the mode symbol is "TDS" (Total Dissolved Solids), pressing the MODE button (top-right) should change it back to "CON."

Related Pages

Water Systems

Cooling water: TF magnets | Vacuum vessel | Thomson scattering | Robicons