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Support Services
Railway Sensors
Telematics
Sensors and Data Acquisition Systems
Through our technology partners, PJ Messtechnik GmbH, we can offer professional advice to help you select the
right sensor to match your requirements and we offer comprehensive after sales technical support to ensure that the measurements
you obtain from the sensors are reliable and meaningful.
PJ Messtechnik puts a lot of effort into research and development to stay at state of the art of technical advances. All their
sensors are used by their engineers when performing static and dynamic field tests. These sensors are fully tried and tested.
PJM LN Sensors
Low noise single-axis accelerometer sensor
The PJM Low Noise (LN) Sensor is a uniaxial accelerometer based on capacitive technology. The PJM LN sensor
range is constructed to achieve precise calibrated static acceleration measurements in real world dynamic situations, under any
weather condition. This is due to its hermetically sealed steel casing which guarantees perfect protection from environmental
influences.
These sensors are are built to resist extreme operating conditions and have magnetic shielding, making them ideal for
taking undistorted measurements on rail vehicles or wayside on track.
They can be used in zero to medium frequency instrumentation applications that require extremely low noise. Due to its internal
Temperature Sensor it is relatively insensitive to temperature changes. The sensors do not exhibit any over-modulation by
temporary observed high-frequency excitations and are particularly suitable for the use in running gear tests and in measuring the
service strength. The sensitive axis is perpendicular to the bottom of the device, with direction of positive acceleration
(output) as shown in figure on the left.
Features
- Vibration Amplitude (g-ranges) from 2 g to 400 g
- Low Noise: 5 μg/–Hz for the PJM LN 2g sensor
- - 55 to + 125 œC Operation Temperature
- Nitrogen Damped / Hermetically Sealed
- ± 4 V Differential with Analogue Output
- Responds to DC & AC Acceleration
- Internal Temperature Sensor
- Low Cross Axis Sensitivity
- Uniaxial, 4 Wire System
- High Shock Resistance
- Magnetic Shielding
- 7 V - 11 V DC Power
- Amplified Output
PJM Triaxial Accelerometer
The PJM 3D Acceleration Sensor is an advancement of the uniaxial accelerometers, which form part of PJM LN
Accelerometer series. The triaxial accelerometer provides an orthogonal reference with a common centre of percussion for up to
three accelerometers which can be fitted with sensor elements of different measurement ranges.
This makes the sensor particularly useful for standard measurement spots (e.g. axle box). Its space saving design enables easy and
versatile placement and reduces the time for mounting considerably.
Features
- Static acceleration measurable (e.g. gravitation)
- No over-modulation at temporary occurring
high-frequency excitation - Excellent for testing running behaviour and
operational resistance - Direct measurement of lateral acceleration
- Sufficient limiting frequency for vibration
measurements - Magnetic shielding
PJM Single Channel Datalogger
The self-sustaining PJM data logger is designed for single channel long time measurements at hotspots. It is
easy to use and ideal for wheel sets, rails and tests of highly stressed components with little available space. It is implemented
in a robust, hermetically sealed casing that resists extreme conditions. An additional ground plate allows very versatile
applications and mounting in many different ways.
Features
- Single-channel data logger for DMS quarter, half and full bridge
- Sample rate 2400 Hz or 4800 Hz
- Amplification for strain gages: 70 - 1280
- Analog filter of 3rd order with a cut-off frequency of 200 Hz (can be increased up to
500 Hz on customer´s demand) - Bridge supply voltage: 3,0 V, short-circuit proof
- Zero balance
- 3.4 V to 15 V DC Power (with integrated acceleration sensor up to 4.2 V)
- Up to three weeks recording at full sample rate (~16 GB)
- Data retrieval via USB 1.1
- Trigger function
- Data type: binary or CSV
PJM 4-16 Channel Datalogger System
The PJM 4-16 channel datalogger system is a self-sustaining, expandable multi-channel data logger for long-
term measurements. Its hermetically sealed casing (protection IP65) assures a high resistance to external influences.
It is designed for synchronous measurements lasting several days. At full sampling rate continuous recordings up to three weeks
are possible.
An expansion up to 16 channels is possible through a synchronous operation of up to four data loggers. The 4-16 channel data
logger system was developed especially for sustainable measurements of rotating convolutions (in particular for wheel sets).
Accuracy of data acquisition is 12 bit. After signal processing data is saved in 16 bit format.
Features
- Single-channel data logger for DMS quarter, half and full bridge
- Sample rate 2400 Hz or 4800 Hz
- Amplification for strain gages: 70 - 1280
- Analog filter of 3rd order with a cut-off frequency of 200 Hz (can be increased up to
500 Hz on customer´s demand) - Bridge supply voltage: 3,0 V, short-circuit proof
- Zero balance
- 3.4 V to 15 V DC Power (with integrated acceleration sensor up to 4.2 V)
- Up to three weeks recording at full sample rate (~16 GB)
- Data retrieval via USB 1.1
- Trigger function
- Data type: binary or CSV
PJM 4-Channel 2.4GHz Telemetry Solution
Especially suited for railway vehicles
The PJM 4-channel-telemetry solution is used for non-contact measurements of moving objects. That is,
telemetry is a desirable solution for areas where cables cannot or are difficult to pass through, such drive trains, axles, gear
shafts, live (energised) pantographs, or any rotating components (e.g. turbines, pumps, etc.).
Particular attention during the development of the telemetry was paid on synchronisation of sampling rates, which guarantees time
synchronisation of all of the 4 channels measured data. Through a constant time-delay, accurate to microseconds, measuring data of
the telemetry can be recorded with exact time correlation to other measured data in the overall system.
Click to view image
The telemetry system consists of transmitter, receiver and corresponding software. The
transmitter unit is powered by an external battery. Transmitter and receiver are connected via WLAN which waives the need for
wiring. Typical measurement parameters could for example include: Forces, Vibration, Torques, Accelerations, Loadings,
or Pressures.
Configuration
Features
- 20 metre transmission range on-board vehicle
- 2kHz sample rate
- 12 bit data resolution
- Battery Powered with up to 500 hours measurement time
- Average power consumption 100 mA
- storage battery 3.7 to 6 V
- RS232 serial interface
- Analogue output +/- 10V
- Adjustable amplified output
