Leak tester 71rel

Relative pressure method
Test on greater leakages
Inexpensive, robust, durable
Leak tester 71rel


We answer your questions:

Tel.: +49 (0) 71 95-13 69 0
eMail: verkauf(at)hematech.de

The Leakage Tester 71rel

HeMaTech Prüftechnik is known for robust, durable leak testers with high accuracy. Users worldwide trust on the reliability and service of HeMaTech Prüftechnik. Leak testers are used for leak testing in industrial applications. Whether in the laboratory or in the production of series parts, our testing devices can be used in a wide variety of applications. Customers from a wide range of industries use our leak testers, including the automotive industry, medical technology and electronics manufacturing.



The cost-efficient alternative

The relative pressure method offers fast results at an attractive instrument price. The test setup is simpler than with differential pressure instruments, such as the 70pro or 75eco. The measurement with the relative pressure method is not as sensitive, but covers a larger measuring range. This makes it ideal for checking components with a larger permissible leakage.

In the leak tester, 10,000 result data sets can be collected for later use. Output is also possible after each measurement, e.g. on a USB stick.

The comprehensive possibilities of automation are available on the 71rel as well.



The functionality of the tester

The applied leak test method according to the differential pressure method offers many advantages for the user. 
The features of the 71rel at a glance:


  • compressed air as a test medium
  • air can quickly penetrate leaks
  • high measuring accuracy
  • reproducible measurements
  • clear measurement results
  • contamination-free testing
  • short cycle times with high accuracy
  • 99 test programmes storable
  • Memory for 10,000 result data sets
  • direct output of results to USB stick
  • automatic test sequence
  • can be integrated into system concepts
  • Profibus and Profinet-interfaces available
  • display of measured value and test result
  • variable test pressures and test times for optimum adaptation to the production of different parts
  • easy handling due to intuitive operator guidance
  • service-friendly due to modular design


Differential pressure measurement technology requires pressure-tight devices and/or sealing elements.
HeMaTech can supply you with complete test stations or systems.



The leak calibrator for the leak tester

As supplementary accessories you will find test leaks as well as a leak calibrator in our range. By means of the test leak, you can check the functionality of your leak tester quickly and easily. The leak calibrator comes as a mobile hand-held device and enables you to perform a reliable calibration at regular intervals. These measures, which can be carried out at any time, ensure a constant quality of your measurements.




A leak tester is always subject to a certain amount of wear during operation and electronic components can change their behavior over time. Therefore, a leak tester should be calibrated and maintained regularly.


We recommend having a calibration performed every 12 months. This can be done at our workshop or at your site.


The calibration laboratory of HeMaTech Prüftechnik is accredited, i.e. we can also carry out DAkkS calibrations.


More information about calibration can be found here.

Operating principle

The operating principle is based on measuring the pressure change in a sealed test part within a given measuring time, the so called differential pressure testing. The core of the measuring system consists of a relative pressure transducer.


Air flows out through a leak in a closed volume (test part). This causes a pressure decay.

The difference between the initial pressure and the pressure at the end of the measuring time can be detected with a relative pressure transmitter. The pressure difference is a measure of the existing leakage and is independent of the test pressure or the prevailing ambient pressure. Inexpensive compressed air is used as the test medium. Due to its low viscosity, the air can quickly penetrate pores, the smallest holes, cracks or other causes of a leak.
The tested parts will not get dirty or contaminated. Rust protection, drying or cleaning is therefore not necessary.
A leak test is only possible with adaptation of the test piece via sealing elements or devices. HeMaTech also offers you a customised concept for this - just ask us.




The test parameters are entered in a clear programme plan and do not require any special prior knowledge. Direct help is available if required. Data is saved via a write-protection key switch. The parameters can only be read, but not changed, when the unit is secured.

Higher-level control systems can communicate with the 71rel via a standard digital I/O interface or optionally via Profibus or Profinet. With Profibus/Profinet, test data and programme parameters can also be exchanged. The 71rel can thus be easily integrated into automated production processes.

Direct input of test programmes at the test instrument can be done very easily via touch screen or an optionally connected keyboard. The units also have an integrated VNC server. As soon as it is connected to a network, the device can be addressed and operated via its IP address and a VNC client.
The USB interface at the front enables the easy storage of measurement data and test programmes of the leak tester.



Pneumatic System

  • industrial gradetransmitter for realtive pressure
  • electronic pressure regulation for filling and test pressure
  • function monitoring
  • optional leak simulation with precision needle valve for the connection of an external leak calibrator or a test leak

Electronic System

  • Windows CE based system
  • Data storage in persistent NAND flash memory
  • Memory for 99 programmes and 10,000 result records
  • 7" touchscreen display
  • virtual keyboard on the touchscreen
  • Remote control via VNC
  • Write protection switch against unauthorised changing of parameters
  • error message in plain text
  • Simple programming
  • Various interfaces for communication with higher-level control systems

Technical data


System:   Windows CE based
Program storage:  

persistent memory, NAND-Flash,
10,000 data records
data record contains information on test programme, date, time, measured value, measurement result, error, test parameter
for larger amounts of data use
external USB storage which
can be connected at the front

Measuring sensor:   temperature compensated transmitter for differential pressure
overload protection 40 bar
Data entry:   virtual keyboard on TFT display
external keyboard via USB, VNC viewer
Display:   7.0" TFT VGA Touch Display
800 x 480 px
Measuring range:   0 ... 6,000 mbar
Resolution:   0.1 mbar
Results:   mbar, ml/min
Test programs:   99
Filling and test Pressure:   electronic pressure control
0.20…6.0 bar/g
Test parameters:   Filling pressure … bar
Test pressure … bar
Pressure tolerance 1.0 … 10.0 % FS
Filling time 0.1 … 999.9 s
Stabilization time 0.1 … 999.9 s
Measuring time 0.1 … 999.9 s
Rework limit …
Reject limit …
Consecutive rejects limit
Write protection:   Key switch
Status indicator:   Accept

1 x parallel interface

(machine control,
up to 96 digital I/Os)
control inputs: 24 VDC, 500 mA
control outputs: 24 VDC, 500 mA
short-circuit proof
    1 x serial interface RS 232 for transfer of parameters and test results
    1x USB 2.0 for transfer of parameters and test results, keyboard, mouse
    1x RJ45 for VNC
optional: Profibus, Profinet
Housing:   compact metal case
Dimensions:   141 x 357 x 420 mm (H x W x D)
Power supply:   110 - 240 V, 50 ... 60 Hz
Power consumption:   Approx. 100 VA
Air supply:   1.5 bar > test pressure,
10 bar max
filtered, dry and oil-free
Pneumatic ports:   air supply G1/4“,
test medium G1/4“ (optional),
test port G1/8“,
reference port G1/8“
vent through air silencer G1/4“
Weight:   Approx. 8 kg
Standard accessories:   leak tester, power cord 2.5 m
key for write protection switch,
USB stick containing manual and
Order-No.:   Leaktester 3925-0071
Specifications and technical data are subject to change without notice.



HeMaTech Prüftechnik GmbH & Co. KG
Siemensstr. 7
D-71409 Schwaikheim


Calibration Service for
Measurand Pressure




Tel.: +49 (0) 71 95-13 69 0
Fax: +49 (0) 71 95-13 69 29
eMail: verkauf@hematech.de


Certified according to
ISO 9001:2015


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