
8.4.3
Temperature measurement and calibration problems
Temperature different from transmitter
1.
Is the standard thermometer, RTD, or thermistor accurate? General purpose liquid-
in glass thermometers, particularly ones that have been mistreated, can have
suprisingly large errors.
2.
Is the temperature element in the sensor completely submerged in the liquid?
3.
Is the standard temperature sensor submerged to the correct level?
8.4.4
Oxygen measurement and calibration problems
Problem
See Section
Zero current is too high.
Zero reading is unstable.
Sensor current during air calibration is sub-
stantially different from expected.
Sensor current different from below
Process and standard instrument readings
during in-process calibration are substantial-
ly different.
Process and standard readings different
Process readings are erratic.
Readings drift.
Sensor does not respond to changes in oxy-
gen level.
Sensor not responding to oxygen changes
Readings are too low.
Zero current too high
The zero current is substantially greater than the values in the table below.
Sensor
Zero current
499ADO
< 50 nA
499ATrDO
< 5 nA
Hx438 and Gx448
< 1 nA
1.
Is the sensor properly wired to the transmitter?
2.
Is the membrane completely covered with zero solution, and are air bubbles not
trapped against the membrane? Swirl and tap the sensor to release air bubbles.
Diagnostics and troubleshooting
Instruction Manual
99
Содержание Rosemount5081
Страница 1: ...Instruction Manual LIQ MAN 5081 Rev A September 2017 Rosemount 5081 Explosion Proof Transmitter ...
Страница 4: ......
Страница 10: ...Contents vi Rosemount 5081 ...
Страница 12: ...Startup procedure 2 Rosemount 5081 ...
Страница 23: ...Mounting 5081 on a pipe Figure 3 2 Installation Instruction Manual 13 ...
Страница 24: ...Installation 14 Rosemount 5081 ...
Страница 28: ...Wiring 18 Rosemount 5081 ...
Страница 50: ...Programming basics 40 Rosemount 5081 ...
Страница 130: ...Diagnostics and troubleshooting 120 Rosemount 5081 ...
Страница 136: ...Digital communications 126 Rosemount 5081 ...
Страница 138: ...NOTICE Consult the factory for additional information regarding service or repair Return of material 128 Rosemount 5081 ...
Страница 140: ...Engineering drawings 130 Rosemount 5081 ...
Страница 141: ...Engineering drawings Instruction Manual 131 ...
Страница 142: ...Engineering drawings 132 Rosemount 5081 ...
Страница 143: ...Engineering drawings Instruction Manual 133 ...
Страница 144: ...Engineering drawings 134 Rosemount 5081 ...
Страница 145: ...Engineering drawings Instruction Manual 135 ...
Страница 146: ...Engineering drawings 136 Rosemount 5081 ...
Страница 151: ...EU Declarations of Conformity 138 Rosemount 5081 ...