Specifications

2/4
Siemens FI 01 · 2015 US Edition
Temperature Measurement
Transmitters for mounting in sensor head
SITRANS TH100 two-wire system (Pt100)
2
■ Overview
The SITRANS TH100 dispenses with electrical isolation and uni-
versal sensor connection to provide a low-cost alternative for
Pt100 measurements.
For the parameterization, the SIPROM T software is used in com-
bination with the modem for SITRANS TH100/TH200.
Its extremely compact design makes the SITRANS TH100 ideal
for the retrofitting of measuring points or for the use of analog
transmitters.
The transmitter is available as a non-Ex version as well as for use
in potentially explosive atmospheres.
■ Benefits
• Two-wire transmitter
• Assembly in connection head type B (DIN 43729) or larger, or
on a standard DIN rail
• Can be programmed, which means that the sensor connec-
tion, measuring range, etc. can also be programmed
• Intrinsically-safe version for use in potentially explosive areas
■ Application
Used in conjunction with Pt100 resistance thermometers, the
SITRANS TH100 transmitters are ideal for measuring tempera-
tures in all industries. Due to its compact size it can be installed
in the connection head type B (DIN 43729) or larger.
The output signal is a direct current from 4 to 20 mA that is pro-
portional to the temperature.
Parameterization is implemented over the PC using the parame-
terization software SIPROM T and the modem for
SITRANS TH100/TH200. If you already have a "modem for
SITRANS TK" (Article No. 7NG3190-6KB), you can continue us-
ing this to parameterize the SITRANS TH100.
Transmitters of the "intrinsically-safe" type of protection can be
installed within potentially explosive atmospheres. The devices
comply with the Directive 94/9/EC (ATEX), as well as FM and
CSA regulations.
■ Function
Mode of operation
The measured signal supplied by a Pt100 resistance thermome-
ter (2, 3 or 4-wire system) is amplified in the input stage. The volt-
age, which is proportional to the input variable, is then converted
into digital signals by a multiplexer in an analog/digital converter.
They are converted in the microcontroller in accordance with the
sensor characteristics and further parameters (measuring
range, damping, ambient temperature etc.).
The signal prepared in this way is converted in a digital/analog
converter into a load-independent direct current of 4 to 20 mA.
An EMC filter protects the input and output circuits against elec-
tromagnetic interferences.
SITRANS TH100, function diagram
Input
Pt100 Resistance thermometer
EMC_1 Input level with protective components
IC Constant current source
MUX Multiplexer
A/D Analog-digital converter
Output
D/A Digital-analog converter
U/I Voltage transformers, current
transformers, constant voltage
and reference voltage source
EMC_2 Output level with protective components
U
aux
Auxiliary power supply
I
out
Output current
Microcontroller
μC Linearization functions and storage
of all data
A/D
D/A
U
aux
, I
out
6
5
3
4
EMC_1
Pt100
MUX
µC
U
I
U
ref
EMC_2
4 ... 20 mA
U
ref
I
c
+
-
© Siemens AG 2015