DQM3 measuring instrument

The DQM is a compact, portable hand-held measuring instrument for the accurate recording of rail head sections at the trackside. Its robust construction allows the DQM to be used under even the most extreme conditions. With over 150 systems in use worldwide, this tried and trusted design has a proven track record for reliability.

Read more about the DQM system and its technical data below or download our DQM leaflet.


Sturdy construction
Robust all-metal construction for daily use in a challenging track construction environment

Compact and portable
Hand-held instrument is quick to deploy and light to carry

Maximum precision
High-quality components ensure 50μm precision

Built-in easy-change battery lasts for at least 250 measurements to provide mains-free outdoor operation

Multilingual menu-driven operation, wireless connection to tablet PC

Trackside real-time evaluation
Instant and simple evaluation and analysis of measurements obtained. Complex evaluation processes can also be performed.


The DQM and all its components are packaged in a carrying case. The track stop and boom are mounted on the measuring head, which forms the heart of the measuring equipment. Mounting is via centring cones and star grips. Once all components are connected and the tablet PC activated and in measurement mode, the measuring instrument is ready for operation. Despite splashproof construction infousing top-quality system components, we recommend the measuring instrument be protected in bad weather.

Measuring procedure

The service-ready DQM is controlled via the connected tablet PC. The software allows the option of recording the gauge of the target cross-section as well as local features along the stretch of track (km, pylons, points, etc.) Once all the entries have been made, the tablet PC transmits the measurement command. Measurement is automatic. A motor draws the securely mounted measurement sensor across the rail from the outside edge of the rail to the running edge. Simultaneously the vertical movements of the sensor are recorded, processed in the measuring instrument, transmitted to the tablet PC and evaluated in real-time. Following measurement, confirmation onscreen returns the sensor to its original position.

Real-time Evaluation, additional evaluation

New Windows®-based evaluation software enables traditional data acquisition to be combined with real-time trackside evaluation. This means the user can see during the measurement process whether the cross-section is compliant with specification. In addition to the track section data, the GPS coordinates of each measurement are stored. A structured archive can be readily created from the extensive positional data. Several modules are available for evaluating more complex measurement tasks. Measured data can be exported in a wide variety of formats.

Product contents

  1. tablet PC (Panasonic Toughbook H2-field)
  2. boom with tensioning hooks (selectable track gauge) and track stop
  3. DQM 3 measuring head
  4. charger
  5. battery
  6. USB cable
  7. manual
  8. carrying case

Technical data DQM3

horizontal measuring range up to 100.0 mm
horizontal resolution 0.1 mm
vertical measuring range 35.0 mm
vertical resolution 0.01 mm
measurement uncertainty (95% CF) < 0.05 mm
measurement time (max. measurement range) approx. 12 s
return time (maximum) 6 s
energy consumption (on standby) 0.25 A
energy consumption (during measurement) 0.49 A
battery type / battery capacity NiMh 12 Volt / > 3.5 Ah
coverage (measurements / battery charge) approx. 200
operating temperature range -10°C to +35°C
weight approx. 9 kg
total weight (incl. case) approx. 22 kg

Tablet PC (Toughbook)

We’ve chosen the Panasonic Toughbook H2-field as the perfect partner for our DQM. The Windows®-based tablet PC has an exceptionally bright 10.1" Transflective-Plus LCD screen with Dual Touch. The batteries are hot-swappable, avoiding any down-time. With its wrist strap the lightweight (1.56kg) tablet is easy to hold, and is vibration and shock resistant and tested to military standards. Additionally water- and dustproof to IP65, it’s ideally suited to use in track laying operations. The integral GPS receiver supplies the locational information for measurements, while the 3-megapixel camera allows any unexpected rail defect to be documented.

Head Height Measurement (optional)

Rail head height can be measured using the mechanism incorporated into the DQM measuring head. When not in use the sensor is held in the retaining shoe on the base plate. If head height measurement is required the sensor is released, rotated through 180° and affixed to the underside of the rail head before recording of the cross-section. The measuring mechanism relays the movement to a laser sensor built into the DQM measuring head. Mechanical scanning means the laser makes no direct contact with the rail, ensuring no errors result from bumps or other factors.

Technical data

measuring range 30 mm
resolution 0.02 mm
measurement uncertainty < 0.05 mm
laser Class 2
laser energy consumption < 100 mA
operating temperature range 0°C to +30°C

Optional accessories

DGM – Digital Gauge Measurement System
The DGM replaces the traditional tensioning hooks with ones incorporating a laser measuring head. Track gauge is then recorded together with the cross-section.

HHM – Head Height Measurement System
The HHM is incorporated into the base plate of the DQM 3 measuring head. The mechanism is moved by hand to the underside of the rail head. The laser built into the DQM 3 measures the movement of the measuring mechanism and records the measured value.

DQM professional software
The flexible and at the same time easy way of assessing measurement data is further processing on the PC. For this purpose, the DQM system offers the DQM Professional software which was especially programmed for the measurement and add-on equipment.
With help from the DQM Professional, the measurements can be imported from the memory card, superimposed on others and saved for archiving purposes.  Different methods are available for the profile analysis and numerical analysis. Output of the measurement curves on the printer and in files is as possible as the transfer of measurement curves into a drawing program.

Target profile
For comparing the measured profile with the specifications or rail head forms of new rails, a multitude of profiles can be delivered as a file. There is an option of creating templates according to customer requests, which is especially useful for special profile attempts.

Plotter case
The mobile plotter case comprises a portable, battery-powered inkjet printer and docking station for the tablet PC. The components within the case are charged via a central plug.

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