TCSMA Conductivity System
Part 6 - Calibration
O & M Manual
22
REV G, 7/2009
Due to the nature of the sensor design, it is
recommended to use the largest range setting
possible for the application when using the 500-
2,500 uS range. The higher instrument ranges are
easier to user calibrate, as they require less back-
and-forth zero/span adjustments. For example,
even though the instrument can be calibrated from
0-500 uS over 4-20 mA, the instrument calibration
will be much easier if the calibration is 0-1000 uS
or 0-2000 uS over the 4-20 mA span.
2. Set these initial settings on other controls:
OFFSET – leave at current position
COARSE SPAN – FULL CCW
FINE SPAN – MID SCALE*
TC
%/°C
–
ADJUST
FOR SOLUTION (see 6.25)
REV/DIR
-
DIR
* Note- control pots are 25 turn. To get to mid position, turn
full CCW until a “clicking” sound is heard, then rotate CW 12
turns.
3. Hold the sensor in air away from any nearby
objects. Sensor should be clean. Adjust the
OFFSET control until the output current from the
transmitter is 4.00 mA.
4. Place the sensor in solution and allow the sensor’s
to temperature equilibrate. To minimize error, it is
best if solution is as close as possible to room
temperature. Allow the system to operate
undisturbed for 15-30 minutes to allow for
temperature element to stabilize. The sensor
must sit in the center of the beaker containing the
conductivity reference solution, without touching
the sides or bottom. Maintain at least 2” clearance
on all sides of the round sensing portion of the
sensor to prevent errors. When first placing the
sensor into solution, swirl slightly and then rap
gently to dislodge any bubbles from the sensor.
5.
Adjust
ROUGH SPAN
until output current is
approximately
20mA
, within approximately 0.5-1.0
mA.
