Product Info
Table Of Contents
iTEMP TMT142
Endress+Hauser 3
Standard diagnostic functions
• Cable open-circuit, short-circuit of sensor wires
• Incorrect wiring
• Internal device errors
• Overrange/underrange detection
• Device temperature overrange/underrange detection
Corrosion detection as per NAMUR NE89
Corrosion of the sensor connection cables can cause incorrect measured value readings. The
transmitter makes it possible to detect corrosion of the thermocouples and mV transmitters, as well
as resistance thermometers and ohmmeters with 4-wire connection, before a measured value is
corrupted. The transmitter prevents incorrect measured values from being exported and can issue a
warning via the HART
®
protocol if conductor resistance values exceed plausible limits.
Low voltage detection
The low voltage detection function prevents the device from continuously transmitting an incorrect
analog output value (caused by an incorrect or damaged power supply system or a damaged signal
cable). If the supply voltage drops below the required value, the analog output value drops to < 3.6
mA for approx. 5 s. The device then tries to output the normal analog output value again. If the
supply voltage is still too low, this process is repeated cyclically.
Diagnostics simulation
Device diagnostics can be simulated. The following items are set during such simulations:
• Measured value status
• Current diagnostics information
• Status bit of HART command 48
• Current output value as per simulated diagnostics
This simulation makes it possible to check that all higher-level systems respond as expected.
Sensor load
An overview function in the device software, which provides time data in relation to how long a
connected sensor is in use in a specific temperature range, makes it possible to record and save data
and values relating to the specific sensor load and to log them as a data record. This makes it
possible to draw long-term conclusions regarding the aging or lifetime of the sensor.
Input
Measured variable
Temperature (temperature-linear transmission behavior), resistance and voltage.
Measuring range
Resistance thermometer
(RTD) as per standard
Designation α Measuring range limits Min. span
IEC 60751:2008
Pt100 (1)
Pt200 (2)
Pt500 (3)
Pt1000 (4)
0.003851
–200 to +850 °C (–328 to +1 562 °F)
–200 to +850 °C (–328 to +1 562 °F)
–200 to +500 °C (–328 to +932 °F)
–200 to +500 °C (–328 to +932 °F)
10 K
(18 °F)
JIS C1604:1984 Pt100 (5) 0.003916 –200 to +510 °C (–328 to +950 °F)
10 K
(18 °F)
DIN 43760 IPTS-68
Ni100 (6)
Ni120 (7)
0.006180
–60 to +250 °C (–76 to +482 °F)
–60 to +250 °C (–76 to +482 °F)
10 K
(18 °F)
GOST 6651-94
Pt50 (8)
Pt100 (9)
0.003910
–185 to +1 100 °C (–301 to +2 012 °F)
–200 to +850 °C (–328 to +1 562 °F)
10 K
(18 °F)
OIML R84: 2003,
GOST 6651-2009
Cu50 (10)
Cu100 (11)
0.004280
–180 to +200 °C (–292 to +392 °F)
–180 to +200 °C (–292 to +392 °F)
10 K
(18 °F)
Ni100 (12)
Ni120 (13)
0.006170
–60 to +180 °C (–76 to +356 °F)
–60 to +180 °C (–76 to +356 °F)
10 K
(18 °F)