Etatron eSelect-CD1, Инструкция по эксплуатации и техническому обслуживанию, Страница: 30 / 36

30 ENGLISH
CONDUCTIVITY SENSORS AND MAINTENANCE
CONDUCTIVITY sensors NOTES
eSelect-CD1 works with simple conductivity 2-electrode open sensors, with AISI 316 and Graphite electrodes.
NOTE FOR CONDUCTIVITY SENSORS
eSelect-CD1 works with simple conductivity 2-electrode open sensors, AISI 316 OR Graphite electrode.
FOR CONDUCTIVITY SENSORS 4 WIRES (with internal temperature sensor): due to the various types on the market, in case
operator wished to use such sensor, please contact ETATRON service or Local Dealer to get the right configuration for
connecting to terminal board.
eSelect-CD1 is NOT suitable for inductive EC sensors !
eSelect-CD1 automatically adjust itself for various conductivity ranges by adapting the controller to the different probes cell costant “K”
characteristic.
Conductivity measurement are in micro Siemens features 4 K factor ranges (Cell Constant) suitable for:
IMPORTANT: the above μS ranges are just indicative, considering that, for example, a K1 probe can make good measurements below 1000
μS, only resolution will be less accurate. However, the same concept does not apply the other way around to higher ranges.
TEMPERATURE CORRECTION (EC alfa factor)
EC alfa factor is the correction factor for conductivity measurement in function of temperature: EVERY CONDUCTIVITY SENSOR IS
TEMPERATURE-DEPENDENT. Conductivity varies linearly according to the temperature of the solution. This coefficient normalize the
measurement of the conductivity at the reference temperature of 25° C. Alfa factor ensures best measurement results and accuracy.
2% per °C is an average found typical of many water samples with some dissolved solids. Over wide temperature spans (e.g. 0 to 100 °C)
the temperature compensation factor may not remain constant,
CONDUCTIVITY sensors maintenance
Sensor Storage
Short term: Rinse the sensor electrodes in demineralised water; allow drying and storing dry.
Long term: Rinse the sensor electrodes in demineralised water, allow to dry, cover with tip with a plastic shipping cap and store dry.
Monthly Maintenance
A monthly maintenance check is recommended by grab sample calibration since the sensor is typically installed in the process and not easy
to remove. Follow the procedure under calibration by grab sample.
Keep a log of the cell constant at each monthly calibration.
When to clean your sensor
Various factors can affect the physical limits on the liquid and the apparent cell constant; scale, biological growths, oils, wax, gum, etc all
reduce the area for current-carrying liquid. Periodic cleaning of conductivity sensors in continuous use will remove these deposits; restore the
conducting surfaces, controlled cell volume, and thus the cell constant.