The WQ-ORP sensor is calibrated with a 1-point calibration in a standard solution with a known ORP, such as Zobell solution, Light’s solution, or quinhydrone-saturated pH buffers. The following table can be used when calibrating with Zobell solution, the NexSens-recommended standard.
Temperature in °C
Zobell Solution in millivolts
- Connect the WQ-ORP sensor to the PC via the USB connector.
- Rinse electrode with distilled or de-ionized water, blot dry, and then place in ORP standard. Current readings will appear on the screen and may take several minutes to stabilize.
- When readings stabilize, press Calibrate and click on the ORP-mV reading. Enter the value of the ORP standard at the corresponding solution temperature. Then press the Calibrate button again.
The calibration process is now complete. Generally, calibration for the ORP probe is not required very frequently. The need to calibrate can be determined by placing the probe in a standard solution. If the probe reads more than +/- 20 mV from the standard value, recalibration is recommended.