Rosemount Analytical 54C, Instruction Manual

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4-2
MODEL 54 C SECTION 4
CALIBRATION
3. Manual temperature slope: If the temperature slope of the process
is known, use the cursor keys to display the temperature slope value
and press Enter(F4). If you do not know the exact temperature slope
value, but wish to approximate it, refer to the following guide.
Acids: 1.0 to 1.6% per °C
Bases: 1.8 to 2.2% per °C
Salts: 2.2 to 3.0% per °C
Water: 2.0% per °C
4. Two point temperature slope calibration: This procedure is used to
calculate the cell constant and temperature slope simultaneously.
This is the recommended procedure for initial calibration if the
process temperature slope is unknown.
A. Obtain a grab sample of the process to be measured. Select tem-
perature slope calibration and press Enter (F4).
B. Determine the sample’s conductivity using a calibrated bench
instrument or portable analyzer. The instrument must be able to
reference the conductivity to 25°C, or the solution must be meas-
ured at 25°C. Write down the reading.
C. Immerse the sensor into the process solution. The sensor body
must be held away from the bottom and sides of the sample’s con-
tainer at a distance at least equal to the diameter of the sensor,
and the sensor cable must not be allowed to contact the solution.
Shake the sensor to ensure that no air bubbles are present.
D. Adjust the sample’s temperature to either the normal high or nor-
mal low temperature of the process. To raise the sample’s temper-
ature, a hot plate with stirrer is recommended. To lower the
process temperature, place the grab sample container in an ice
bath or let it slowly cool down.
E. Allow the sensor to acclimate to the solution. (The temperature
reading should be stable.)
200.0 mS/cm
Sample: 2 00.0 mS/cm
at 1st temp: 25.0°C
Exit Tmp 2 Enter
200.0 mS/cm
Sample: 2 00.0 mS/cm
at 2nd temp: 100.0°C
Exit Tmp 1 Enter
Manual slope input
Temp slope calibration
Exit Enter
Manual slope input
Temp slope calibration
Exit Enter
Temp slope: 2 .00 %/°C
Exit Enter