TEL1-FM
One channel telemetry system for
rotating applications,
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TEL1-FM-Telemetry System for Strain Gage Applications on Rotating Shafts TEL1-FM
stands for an equally cost-efficient, comfortable and powerful solution
for the wireless inductive transmission of strain gage signals from
rotating shafts offered by Kraus Messtechnik GmbH (KMT). The extraordinary
high signal bandwidth of 0 to 10 kHz makes the system especially suitable
for the acquisition of high-frequency torsional vibrations. The large
maximum distance of 100 mm between the rotating drive-shaft and the static
pickup device is surely another high-light which guarantees for a
continuous and error-free reproduction of the signal even in applications
where extreme excentrical movements of the shaft occur.
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very small and light-weighted modules (70 x 16 x 5 mm, 15 grams each) form
the rotating part of the system including the signal conditioning and
frequency modulation electronics. The transmitter modules as well as the
indtion winding are simply mounted to the drive-shaft by means of a
special fibre-armed tape. Mounting them in opposite positions provides an
easy way of balancing the additional masses. Strain gage sensors (³
350 Ohm) in full-, half- and quarter-bridge configuration may be directly
connected to the transmitter. The system offers a fixed excitation of 4
Volt DC and four different gain settings (0.5 mV/V, 1mV/V, 2.5 mV/V,
5mV/V) which can be selected by jumpers. An automatic zero adjustment (“Auto-zero”)
is executed by a short connection of the appropriate external AZ pins. The
Auto-zero setting is stored in a Flash-RAM and thus not lost during
power-off. An external shunt calibration (positive and negative) may also
be performed. The electrical power for the transmitter modules (6-12 VDC,
max. 70 mA) can be supplied either by battery or inductively (as an option).
However, with inductive powering the maximum transmission distance is 10
to 20 mm only.
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The
modulated signal is inductively transmitted to a static pickup coil and
then transferred to the receiver by cable (max. length 10 meters). The
receiver and reproduction unit offers two BNC connectors at the front
panel with analog outputs of ±
5V and ±
10 V. An LED bar indicator shows the actual level and a successful AZ
calibration. Overload is indicated by the last LEDs in pos. or neg.
direction. These OVL-LEDs operate in peak-hold mode and must be reset by
pressing the overload switch. A potentiometer enables the fine tuning of
offset and gain. Transmission and
distance errors (> 100mm) are separately indicated. The transmitter
modules (except the connector pins) and the pickup device are protected
against water and dust intrusion. KMT specifies an overall accuracy of ±
0.5 % (without sensor). |
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For more details see PDF Data sheets |
