Emerson Rosemount 56, Инструкция по эксплуатации

Страница: 119 / 136

Profibus Communications 109
Instruction Manual Section 12: Profibus Communications
LIQ-MAN-56 April 2017
Table 12-14. Signal Board Diagnostic Bits – continued
Conductivity Faults and Warnings
Signal
Board 1 / 2
GSD Descriptor Help
109 / 141 SN 1/2 Out Of
Range Cont/Tor
Brd
Contacting Conductivity Measurements
The raw conductance is greater than 1 S.
1. Check sensor wiring.
2. Check sensor cleanliness.
3. Check the sensor electrodes for shorts.
Toroidal Conductivity Measurements
The raw conductance is greater than 2 S.
1. Check sensor wiring.
2. Check sensor electrodes for shorts.
112 / 144 SN 1/2 -ve Rdng
Cont/Tor Brd
(Warning)
(Negative
conductivity
reading)
Contacting Conductivity Measurements
Negative Reading:
During zero calibration, the analyzer makes a correction for the conductance equiv-
alent of the cable capacitance. If the difference between the measured conduc-
tance and the zero correction is less than -2 uS, the negative reading warning
appears.
1. Repeat zero calibration. Be sure the sensor is completely dry.
2. Confirm that the sensor is completely submerged in the process liquid.
Toroidal Conductivity Measurements
Negative Reading:
During zero calibration, the analyzer makes a correction for small offsets in the sig-
nal that exist even when the conductance is zero. If the difference between the
measured conductance and the zero correction is less than -50 uS, the negative
reading warning appears.
1. Repeat zero calibration. Be sure the sensor is completely dry.
2. Confirm that the sensor is completely submerged in the process liquid.
113 / 145 SN 1/2 % Out Of
Range
(Warning)
The calculated concentration or temperature is out of range.
1. NaOH: 0 – 12.00%, 0 - 100 °C.
2. HCl: 0 – 15.00%, 0 - 65 °C.
3. H
2
SO
4
(low): 0 – 25.00%, -1 - 99 °C.
4. H
2
SO
4
(high): 96.0 – 99.7%, 4 - 110 °C.
5. NaCl: 0 – 20.00%, 0 - 100C.
6. Salinity: 2 – 42 part per thousand, -2 - 35 °C.
Amperometric Faults and Warnings
Signal
Board 1 / 2
GSD Descriptor Help
110 / 142 SN 1/2 -ve Rdng
Amp/Oxy Brd
(Warning)
(Negative
amperometric
reading)
The analyzer subtracts the zero current (the current generated by the sensor when
no analyte is present) from the measured current before converting the result into
a concentration value. A negative reading implies the zero step was done before
the sensor reached a stable zero current. Repeat the zero calibration. It august re-
quire several hours or as long as overnight for the zero current to stabilize.
114 / 145 SN 1/2 Pressure
Sensor Broken
(Warning)
The pressure sensor on the oxygen sensor board has failed, or it is not installed, or it
is installed backwards. Replace the sensor board.