Specifications

2/89
Siemens FI 01 · 2015 US Edition
Temperature Measurement
SITRANS TS500
Technical description
2
Vibration resistance of measuring insert, cable sensor
Similar to the thermowell, inner (Karman vortices) and outer
(plant) vibrations also affect the measuring insert. For this rea-
son, a special assembly of measurement elements is required.
Other than a few exceptions for cable and compact thermome-
ters, Siemens only produces sensors based on a mineral-insu-
lated cable. Together with precautions taken when installing the
measuring element, the Siemens basic version already exceeds
EN 60751 by more than a factor of 3. Pursuant to the measure-
ment methods of this standard, the following values are obtained
(tip-tip):
• 10 g: Basic version and expanded measuring range
• 60 g: Increased vibration-resistance and thermocouple
Bending ability of measuring insert/cable sensor
All Siemens measuring inserts SITRANS TSinsert are made with
a mineral-insulated cable (MIC). The same applies to a portion
of the cable and compact thermometer. In addition to the prop-
erties already described, another advantage of the MIC is its
bending ability. This makes it possible to install these thermom-
eters even in difficult to access areas. Please ensure that you are
not below the following bending radius:
Where a smaller bending radius is required due to installation
conditions, subsequent testing of the insulation resistance is
recommended.
Electrical stability
Insulation resistance
The insulation resistance between each measuring circuit and
the fitting is tested at a voltage of 500 V DC at room temperature.
R
iso
 100 M
Due to the property of the mineral-insulated cable, the insulation
resistance decreases as temperature increases. Because of the
special production method, it is, however, possible to achieve
very good values even at high temperatures.
Line resistance
When connected to two-wire systems, the line resistance is in-
cluded in the measurement result. The following rule of thumb
can be used:
•  Measuring insert 3 mm (0.12 inch) 5 /m or 12.8 °C
(55.04 °F)
•  Measuring insert 6 mm (0.24 in) 2.8 /m or 44.78 (44.78 )
For this reason a connection to three- or four-wire systems is
highly recommended.
Ø MIC [mm (inch)] R
min
= 4x Ø MIC [mm (inch)]
3 (0.12) 12 (0.48)
6 (0.24) 24 (0.95)
© Siemens AG 2015