Data Sheet

DATA SHEET
Technical changes reserved
Application range
In the area of building instrumentation, there is a requirement for rea-
sonably priced temperature probes which are suitable for continuous
operation and protected against over voltage and transients. Further
aspects are DC / AC supply, high long term stability as well as a good
measuring accuracy in the application. The B+B temperature probes
of -GLT series are developed for these requirements and are spe-
cially suitable for application in this area due to the modern sensor
technology and innovative construction with an ASIC.
The measurement of temperature is done with a precise and long
term stable platinum resistance with industrial suitability. The proces-
sing of resistance curve is linearised over a second order polynomial
as per DIN 47115. With electronic signal processing, the temperature
values are converted into a standard signal of 0 ... 10 V or 4 ... 20mA.
The voltage supply for the 0 ... 10 V model can be done alternatively
with AC or DC supply. The 4 ... 20 mA model is meant for only DC
supply.
The sensor is mounted in a protection tube of high grade stainless
steel 1.4571 and is also suitable for measurement in liquid media or
for mounting in ventilation ducts. Because of the extended probe and
thermally insulated electronics, self heating is avoided and hence a
higher precision level is achieved in temperature measurement.
Supply
For 4 ... 20 mA model, only DC supply is possible. The 0 ... 10 V
model can be alternatively fed with either DC or AC voltage and also
withunlteredrectiedvoltage.
In case of AC supply, the neutral point of the transformer must be
connected to signal ground and the connection of further probes
must be absolutely done with phase balance. In case of supply with
rectiedunlteredvoltage,theminusmustbeconnectedtoreference
ground and plus to be connected to +DC / AC 24 V. Wrong connec-
tion leads to malfunctioning or can cause damage to the electronics!
Calibration
The measuring probes are calibrated by a precision resistance
decade with reproducibility of PTB National standard. Calibration
certicateasperISO9000standardisalsoavailablewithsomeextra
charges.
Setting
Because of the high grade platinum sensor element, the probe is
long term stable and maintenance free. Hence, a re-calibration is not
required as per practice.
The calibration connector is preserved only for factory purpose and
must not be connected.
Measurement of signal voltage
In order to avoid measuring error in the 0 ... 10 V model due to line
resistanceandcurrentowthroughthegroundingwire,aseparate
grounding wire is to be used for the signal voltage. The voltage mea-
surement should be with a four wire system.
Connection
Preferably shielded connection cable should be used for the connec-
tion. First of all, it is to be noted that in EMI disturbed environment,
the shielding should be grounded. Check before connection, whether
thesupplyvoltageisasperoperatingvoltagespecicationmentioned
in the data sheet .
Mounting of measuring probes
For mounting of external measuring probes, commercially available
bayonetconnectorsormountingangescanbeused.Pleaseaskfor
our accessories overview. Because of the protection tube, the probe
is liquid proof and pressure tight. The projected measuring probe type
-INT can be directly mounted on the ventilation ducts. Drill holes for
the probe and two mounting screws with the help of enclosed drilling
template. Directly mount the probe on the ventilation duct with a
gasketinbetween.Alternatively,amountingangeisavailablewith
clamping ring / clamping screws.
Drillingtemplateformeasuringamplier
Temperature probe with transducer
Series TF-GLT
B+B Thermo-Technik GmbH | Heinrich-Hertz-Straße 4 | D-78166 Donaueschingen
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