Procedure - Zeroing The Sensor - Emerson Rosemount TCL Manual

9.3.2

Procedure - zeroing the sensor

Complete the following steps to calibrate the sensor with the zero standard.
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Instruction Manual
Remove the sensor from the flow cell and place it in a beaker of deionized water. Be
sure no air bubbles are trapped against the membrane. Observe the sensor current.
The current drops rapidly at first and then gradually reaches a stable zero value.
To monitor the sensor current, press DIAG.
Move the cursor to the chlorine sensor and press ENTER.
The input current is the first line in the display. Note the units: nA is nanoamps; uA is
microamps. Typical zero current for a 499ACL-02 sensor is -10 to +50 nA. A new
sensor or a sensor in which the electrolyte solution has been replaced may require
several hours (occasionally as long as overnight) to reach a minimum zero current.
Important
Do not start the zero routine until the sensor has been in the zero solution for at least two
hours.
Press MENU.
The main Menu screen appears. The cursor is on Calibrate.
Press ENTER.
Choose the sensor you wish to calibrate.
Sensor 2 only appears if you have a dual input Rosemount 1056 Transmitter.
Choose Total Chlorine.
Calibration
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