SITRANS T measuring instruments for temperature
Transmitters for rail mounting
SITRANS TW
four-wire system, universal, HART
3/40
Siemens FI 01 · 2010
3
Thermocouple elements
Measured variable
Temperature
Measured range
Parameterizable
Measured span
Min. 50 °C (32.22 °F) x 1/scaling
factor
Measuring range limits
Depend. on type of thermocouple
element
Thermocouple
• Type B
Pt30 %Rh/Pt6 %Rh (DIN IEC 584)
• Type C
W5 %-Re (ASTM 988)
• Type D
W3 %-Re (ASTM 988)
• Type E
NiCr/CuNi (DIN IEC 584)
• Type J
Fe/CuNi (DIN IEC 584)
• Type K
NiCr/Ni (DIN IEC 584)
• Type L
Fe-CuNi (DIN 43710)
• Type N
NiCrSi-NiSi (DIN IEC 584)
• Type R
Pt13 %Rh/Pt (DIN IEC 584)
• Type S
Pt10 %Rh/Pt (DIN IEC 584)
• Type T
Cu/CuNi (DIN IEC 584)
• Type U
Cu/CuNi (DIN 43710)
Special type
(-10 mV
≤
UTC
≤
100 mV)
Voltage measurement
Temperature-linear, voltage-linear
or customer-specific
Type of connection
• Normal connection
• Sum connection
• Mean-value connection
• Differential connection
Cold junction compensation
None, internal measurement, exter-
nal measurement or predefined
fixed value
Sensor breakage monitoring
Function can be switched off
mV sensors
Measured variable
DC voltage
Measured range
Parameterizable
Measured span
Min. 4 mV
Input range
-120 ... +1000 mV
Voltage measurement
Voltage-linear or customer-specific
Overload capacity of inputs
Max.
±
3.5 V
Input resistance
≥
1 M
Ω
Sensor current
Approx. 180
µ
A
Sensor breakage monitoring
Function can be switched off
V sources
Measured variable
DC voltage
Measured range
Parameterizable
Voltage measurement
Voltage-linear or customer-specific
Input range/min. span
• Devices with 7NG3242-xxxx
1
or
7NG3242-xxxx
0
with U/I plug
-1.2 V ... +10 V/0.04 V
• Devices with 7NG3242-xxxx
2
-12 V ... +100 V/0.4 V
• Devices with 7NG3242-xxxx
3
-120 V ... +140 V/4.0 V
Sensor breakage monitoring
Not possible
µ
A, mA sources
Measured variable
DC voltage
Measured range
Parameterizable
Voltage measurement
Current-linear or customer-
specific
Input range/min. span
• Devices with 7NG3242-xxxx
4
-12
µ
A ... +100
µ
A/0.4
µ
A
• Devices with 7NG3242-xxxx
5
-120
µ
A ... +1000
µ
A/4
µ
A
• Devices with 7NG3242-xxxx
6
-1.2 mA ... +10 mA/0.04 mA
• Devices with 7NG3242-xxxx
7
or
7NG3242-xxxx
0
with U/I plug
-12 mA ... +100 mA/0.4 mA
• Devices with 7NG3242-xxxx
8
-120 mA ... +1000 mA/4 mA
Sensor breakage monitoring
Not possible
Output
Output signal
Load-independent direct current
0/4 ... 20 mA, can be switched to
load-independent DC voltage
0/2 ... 10 V using plug-in jumpers.
Current 0/4 ... 20 mA
• Overrange
-0.5 ... +23.0 mA, continuously
adjustable
• Output range following sensor fault -0.5 ... +23.0 mA, continuously
adjustable
• Load
≤
650
Ω
• Open-circuit voltage
≤
30 V
Voltage 0/2 ... 10 V
• Overrange
-0.25 ... +10.75 V, continuously
adjustable
• Output range following sensor fault -0.25 ... +10.75 V, continuously
adjustable
• Load resistance
≥
1 k
Ω
• Load capacitance
≤
10 nF
• Short-circuit voltage
≤
100 mA (not permanently short-
circuit-proof)
• Electrical damping
- Adjustable time constant
T
63
0 ... 100 s, in steps of 0.1 s
• Current source/voltage source
Continuously adjustable within the
total operating range
Sensor fault/limit signalling
By operation indicator, relay output
or HART interface
Operation indicator
Flashing signal
• Limit violation
Flashing frequency 5 Hz
• Overrange
Flashing frequency 1 Hz
Relay output
Either as NO or NC contact with
1 changeover contact
• Switching capacity
≤
150 W,
≤
625 VA
• Switching voltage
≤
125 V DC,
≤
250 V AC
• Switching current
≤
DC 2.5 A
Overrange
Signalling of sensor or line break-
age and sensor short-circuit
Limit monitoring
• Operating delay
0 ... 10 s
• Monitoring functions of limit
module
• Sensor fault (breakage and/or
short-circuit)
• Lower and upper limit
• Window (combination of lower
and upper limits)
• Limit and sensor fault detection
can be combined
• Hysteresis
Parameterizable between 0 and
100 % of measuring range
© Siemens AG 2009
