28
Addendum 3: Calculating Temperature Coefficients
To determine the temperature coefficient of your sample solution use this formula:
C
T2
- C
T1
TC
= 100 x _______________________
C
T1
(T
2
- 25) - C
T2
(T
1
- 25)
TC
= Temperature coefficient
C
T1
=Conductivity at Temp. 1
C
T2
= Conductivity at Temp. 2
T
1
= Temp. 1
T
2
= Temp. 2,
25
= 25°C
NOTE:
A controlled temperature water bath is ideal for this procedure.
1. Immerse the probe into a sample of solution and adjust the temperature coefficient to 0%
(that is, no compensation) by entering setup program P1.1 and pressing the MR/
▼
button until
the upper display shows 0.0 and press ENTER. Press CAL/MEAS to come back to conductivity
measurements.
2. Wait for 5 minutes. Note T1 and CT1 (conductivity at t1).
3. Condition the sample and probe to a temperature (T2°C) that is about 5°C to 10°C different from
T1, and note the conductivity reading CT2.
NOTE:
Record your results for future reference in the back of this manual. Ideally T1 and T2 should
bracket your measurement temperature, and should not differ by more than 5°C.
4. Enter the Temperature Coefficient in the meter. While in program P1.1, use MI/
▲
or MR/
▼
.
5. Scroll to a required value from 0.0 to 10.0%/°C as determined in the procedure outlined above.
6. Once this value is displayed, press ENTER to confirm the value. This coefficient will now be
applied to all the meter readings.
Addendum 4: Calibration Tips
You only need one calibration for measurement throughout the entire range of the meter. If a range
was not calibrated, the meter automatically detects the closest range calibrated and uses that calibra-
tion information. However, only the ranges that were calibrated have maximum accuracy.
If you are measuring in ranges greater than 20 mS or conductivity lower than 100 µS, calibrate the
meter at least once a week to get specified ±1% F.S. accuracy. If you are measuring in the mid
ranges and you washed the probe in deionized water and stored it dry, calibrate the meter at least
once a month. Wet the probe for 10 minutes before calibrating or taking readings to saturate the
probe surface and minimize drift. If you make measurements at extreme temperatures, calibrate the
meter at least once a week.
NOTE:
Use only the conductivity probe specified for these meters. If you do not, you must measure
the solution temperature separately and manually enter the solution temperature.
warranty/
return of items
appendix
accessories
specifications
error
messages/
troubleshooting
probe care
and
maintenance
setup
program
conductivity
measurement
temperature
calibration
conductivity
calibration
starting up
introduction
Summary of Contents for WD-35610-00
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