Simulating Inputs - Ph - Emerson Rosemount FCL Reference Manual

Reference Manual
00809-0200-3412
9.9

Simulating inputs - pH

9.9.1 General
This section describes how to simulate a pH input into the transmitter. To simulate a pH
measurement, connect a standard millivolt source to the transmitter. If the transmitter is
working properly, it will accurately measure the input voltage and convert it to pH.
9.9.2 Simulate pH input
This section describes how to simulate a pH input into the transmitter. To simulate a pH
measurement, connect a standard millivolt source to the transmitter. If the transmitter is
working properly, it will accurately measure the input voltage and convert it to pH.
Procedure
1. Set automatic temperature correction to Manual and set manual temperature to 25
2. Disconnect the sensor and jumper wire between the IN REFERENCE and IN pH
3. Press INFO and choose sensor 2 (pH).
4. If a standard millivolt source is available, disconnect the jumper wire between IN
5. Calibrate the transmitter using the manual buffer procedure.
6. To check linearity, set the voltage source to the value shown in the table and verify
Rosemount FCL 56
°C.
See Temperature.
terminals.
The input voltage should be 0 mV, and the pH should be 7.00. Because calibration
data stored in the transmitter may be offsetting the input voltage, the displayed pH
may not be exactly 7.00.
REFERENCE and IN pH and connect the voltage source as shown in
Figure 9-2: Simulating pH input
Be sure to jumper the IN REFERENCE and GND SOL terminals.
Use 0.0 mV for Buffer 1 (pH 7.00) and -177.4 mV for Buffer 2 (pH 10.00).
If the transmitter is working properly, it should accept the calibration. The slope
should be 59.16 mV/pH, and the offset should be zero.
that the pH and millivolt readings match the values in the table.
Voltage (mV)
295.8
177.5
59.2
-59.2
-177.5
Figure
pH (at 25 °C)
2.00
4.00
6.00
8.00
10.00
Troubleshoot
May 2019
9-2.
57