Instruction manual

50
MODEL XMT-C SECTION 8.0
CALIBRATION — CONDUCTIVITY
8.2 ZEROING THE INSTRUMENT
This procedure is used to compensate for small offsets to the conductivity signal that are present even when there
is no conductivity to be measured. This procedure is affected by the length of extension cable and should always
be repeated if any changes in extension cable or sensor have been made. Electrically connect the conductivi-
ty probe as it will actually be used and place the measuring portion of the probe in air.
Complete the following procedure. Verify that the sensor is actually in air. If the displayed value is not very
close to zero, then press ENTER. The transmitter will establish a new zero.
1. If continuing from the previous procedure, the screen on the left will
appear.
2. Choose Conductivity. Press ENTER.
3. Choose Zero. Press ENTER. The screens at the left will appear briefly
during zeroing.
After a few seconds, the display will return to a value of 0 µS/cm and
may then change slightly. A slight variation from zero is to be expect-
ed, and the procedure may be repeated several times, if necessary. A
successful zero is indicated with a message of "Sensor Zero Done".
An unsuccessful zero will result if the conductivity reading is more than
1000 µS/cm or if the reading is too unstable. The "Zero offset error"
message indicates the reading is too high for the zero routine. If
repeated attempts do not result in an acceptable zero, there is a good
chance that there is a wiring problem.
4. After electronic zeroing, the Conductivity menu screen will appear.
Live 0.000μS
Sensor Zero Done
Live 1.000μS
Zeroing
Wait
Calibrate
Hold
Program Display
Cal?
Conductivity
Temperature
Ca? InProcess
Meter
Zero
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