Instruction manual

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7.3 CONFIGURING AND RANGING THE OUTPUT (-HT version only)
7.3.1 Purpose
1. Configuring an output means
a. displaying the output reading in units of mA or percent of full scale.
b. changing the time constant for output dampening.
c. assigning the value the output current will take if the transmitter detects a fault in itself or the sensor.
2. Ranging the output means assigning values to the 4 mA and 20 mA outputs.
3. Testing an output means entering a test value from the keypad to check the operation of recorders or con-
trollers.
4. Trimming an output means calibrating the 4 and 20 mA current outputs against a referee milliammeter.
7.3.2 Definitions
1. CURRENT OUTPUT. The transmitter provides a continuous 4-20 mA output current directly proportional to
the pH of the sample.
2. FAULT. The transmitter continuously monitors itself and the sensor for faults. If the transmitter detects a
fault, the 4-20 mA output can be programmed to go to a fixed value or it can be programmed to continue
to display the live current reading. In any event Fault appears intermittently in the second line of the dis-
play.
3. DAMPEN. Output dampening smoothes out noisy readings. But it also increases the response time of the out-
put. To estimate the time (in minutes) required for the output to reach 95% of the final reading following a step
change, divide the setting by 20. Thus, a setting of 140 means that, following a step change, the output takes
about seven minutes to reach 95% of final reading. The output dampen setting does not affect the response
time of the process display. The maximum setting is 255.
4. TEST. The transmitter can be programmed to generate a test current.
MODEL XMT-P pH/ORP SECTION 7.0
PROGRAMMING THE TRANSMITTER