Corrosion Detection - Endress+Hauser iTEMP HART TMT162 Bedienungsanleitung

TMT162
S1 defective
S2 defective
S1 and S2 defective
Drift alarm
(IS1-S2I > limit value)
Drift warning
(IS1-S2I > limit value)
Endress+Hauser
Fault code Cause
206 Warning:
Sensor 1 corrosion
207 Warning:
Sensor 2 corrosion
208 Unit reset to factory default values
209 Device initialization
+1000 Other faults active
1) The modes have the following meaning: F: Fault, C: Device in service mode, M: Maintenanca required,
S: Out of specification, *: depends on mode (F or M). See also section 6.4.2 Supported HART
If more than one fault is active, then the fault with the highest priority will be
displayed. Once this fault has been remedied the next fault is displayed! Multiple
fault occurances can be recognized by an "Offset" of 1000.
Unit reaction to sensor faults
PV = SV1
(2 Sensor inputs)
Fault
Warning
Fault
-
-
The icon "Warning" and error code appear in the display on warnings and errors. On error,
the bargraph in the display also flashes - instead of the measured value only the error code
is displayed. (See also chapter 5.2).
9.2.1

Corrosion detection

Corrosion detection only for RTD 4-wire connection.
Sensor connection cable corrosion can lead to false measured value readings. Therefore our
unit offers the possibility to recognize any corrosion before the measured values are affected.
There are 2 different steps selectable dependent on the application requirements:
• off (warning output just before reaching the alarm set point. This allows preventative
maintenance/trouble-shooting to be done).
• on (no warning. immediate alarm)
The following table shows the reaction of the device on sensor cable connection resistance
change. These also indicate the reaction dependent on the parameter selection on/off.
1)
RTD
off
on
Pt100 = 100  at 0 °C (32 °F), Pt1000 = 1000  at 0 °C (32 °F)
1)
Action/Remedy
Monitor sensor 1
Monitor sensor 2
-
-
Remove displayed faults
PV = SV1 - SV2 PV = (SV1+SV2)/2
(Differential) (Average value)
Fault
Fault
Fault
Fault
Warning
<  2 k 2 k  < x <  3 k
--- WARNING
--- ALARM
Trouble-shooting
PV = SV1 (or SV2)
(Sensor back-up)
Fault Warning
Fault Warning
Fault
Fault
Warning Warning
>  3 k
ALARM
ALARM
1)
Mode
M
M
0
0
®
commands.
Fault
Fault
87