3. Specifications
Thermometer with transmitter and output signal 4 ... 20 mA (models TR21-x-ZTT
and TR21-x-ZTB)
Total measuring deviation in
accordance with IEC 60770
Basic configuration
Analogue output
Linearisation
Linearisation error
Switch-on delay, electrical
Warming-up period
Current signal for error signalling Configurable in accordance with NAMUR NE43
Sensor short-circuit
Sensor current
Load R
A
Effect of load
Power supply U
B
Max. permissible residual ripple
Power supply input
Power supply effect
Influence of the ambient
temperature
Electromagnetic compatibility
(EMC)
6)
Temperature units
Info data
Configuration and calibration data Permanently stored
Response time (measurement in
accordance with IEC 60751)
Electrical connection
Autoclavability (option)
Readings in % refer to the measuring span
1) The temperature transmitter should therefore be protected from temperatures over 85 °C (185 °F).
2) Through their small design, face-sensitive measuring resistors serve to reduce the heat dissipation with short insertion
lengths. Available for the temperature range up to 150 °C (302 °F).
For thermowell insertion lengths of less than 50 mm, face-sensitive measuring resistors are recommended.
For thermowell insertion lengths of less than 11 mm, face-sensitive measuring resistors are generally used.
3) Class accuracy A only valid in the temperature range -30 ... +150 °C (-22 ... +302 °F) or -30 ...+250 °C (-22 ... +482 °F),
otherwise class B
4) ±0.2 % for measuring ranges with a lower limit less than 0 °C (32 °F)
5) Use resistance thermometers with shielded cable, and ground the shield on at least one end of the lead, if the lines are
longer than 30 m or leave the building. The instrument must be operated grounded.
6) During transient interferences (e.g. burst, surge, ESD) take into account an increased measuring deviation of up to 2 %.
WIKA operating instructions model TR21
Measuring deviation of the measuring element + the transmitter
Measuring range 0 ... 150 °C (32 ... 302 °F), other measuring
ranges are adjustable
4 ... 20 mA, 2-wire
Linear to temperature per IEC 60751
±0.1 %
4)
max. 4 s (time before the first measured value)
After approx. 4 minutes, the instrument will function to the
specifications (accuracy) given in the data sheet.
downscale ≤ 3.6 mA
not configurable, in accordance with NAMUR NE43 downscale
≤ 3.6 mA
< 0.3 mA (self-heating can be ignored.)
R
≤ (U
- 10 V) / 23 mA with R
A
B
±0.05 % / 100 Ω
DC 10 ... 30 V
10 % generated by U
B
protected against reverse polarity
±0.025 % / V (depending on the power supply)
0.1 % of span / 10 K T
a
2004/108/EC, EN 61326 emission (group 1, class B) and
interference immunity (industrial application)
20 % of the full measuring range
Configurable °C, °F, K
TAG No., description and user message can be stored in
transmitter
t
< 4.7 s
t
< 12.15 s
50
90
M12 x 1 circular connector (4-pin)
Autoclavable with mounted protection cap at connecting plug
(for further details, see „Ambient conditions")
upscale ≥ 21.0 mA
in Ω and U
in V
A
B
< 3 % ripple of the output current
5)
EN
, configuration at
9