We have developed high dynamical pressure test units for pulsation tests for many different customers. The pressure range for the quick pulsation up to 100 Hz can be up to 500 bar. For slower pulsation tests the pressure range is available to 3000 bar.
Below is an excerpt from our different projects:
Pressure simulation unit
The dynamical pressure simulation unit PRO250HY is used for example for the lifetime tests of pressure sensors that are used in the motor management of combustion engines. The unit is equipped with a nitrogen inerting and a temperature chamber and is certified according to ATEX for the operation with potentially explosive mediums.
Task:
Due to the ever-increasing requirements for the reduction of the emissions of petrol and diesel engines, for the manufactuer of engines the necessity arises to develop individual motor managements systems. Different cylinders on the one hand and the requirements/ service conditions on the other hand had to be taken into consideration.
Therefore it is necessary to use pressure sensors for measuring the combustions processes. The pressure sensors have to prove their practicality in endurance tests or life time simulations tests.
For verification of the pressure sensor specifications, their output signals are first measured at different pressure levels, correction data for them is calculated and these information is afterwards programmed in the sensors or in the evaluation electronics. Then the review – the so called calibration – in the true sense is performed.
The environmental conditions for the specimen are simulated by the climate chamber or the streamer/ shaker. It is required that the test conditions (pressure simulation) are fulfilled at the temperature of -40° to +150°C – so the test medium temperature has to be determined for this compatibility. Temperature changes must not influence the physical set pressure.
Temperature curves of different temperature levels with defined temperature change gradients and corresponding pressure levels are passed through.
After these first tests, for some random samples follows an endurance or life time test for e.g. 109 cycles.
For the simulation of the pressure cycles the similiarity to the later operating environment of the sensor is to be strived for. Therefor you can define a frequency in the range of
0…75 Hz with the PRO250HY.
During the cycle test the limits of the sensors and their supply voltage are monitored to detect any short circuits or distortion of the output signal.
Unit concept:
The hydraulic pressure test unit PRO250HY allows a PC operated pressure increase up to 250 bar static and dynamical 0…75 Hz.
The outlet pressure is generated via media separation if the testing medium is not a hydraulic oil but e.g. a predefined liquid (for example a diesel test oil acc. to ISO 4113). If a specimen has any leakages and/ or air inclusions, they will be compensated by the control unit. Also in case of a medium separation the testing medium is refilled automatically.
The PRO250HY is supervising, calibrating and working largely fully automatical.
In case of an error, the test unit switches off. The status of the test bench is permanently logged in a database.
The components of the unit are either mounted in two screwed console housings or in switchboards.
Measurement electronic boards are providing the specimen with adjustable supply voltage and measure the outlet signals.
The electric contacting of the specimen is usually realized via plugs or via individually produced contactings for the parts to be tested.
Pressure distributor units are especially modified to the specimen and further the knowledge about optimized ventilation and safety requirements are taken into account.
The picture shows the white outlines for a climate chamber for simulating the environmental conditions. Because of safety reasons, in case of testing at high temperatures a protection area (e. g. with nitrogene overpressure) is mandatory in order to avoid the arising of an EX atmosphere.
The pressure safety during the burst test is solved with special attention.
Software:
In the test unit operation a micro controller is integrated that is handling the communication with a PC via RS232 interface.
The software – written with © LAB-VIEW – provides the PRO250HY as a “virtual instrument” to the other program modules.
The calibration and service functions of the PRO250HY are carried out with the software or with a terminal program via interface, e.g. linearization of the reference pressure transducer.
Summary:
- Measuring range: 0..250 bar
- Reference pressure sensor: with characteristic curves linearization: system failure <0,05% of full scale
- Pressure simulation:
- Static: 0..250 bar
- Dynamical 0..200 bar, 0..75 Hz; for special application up to 100 Hz
- Ramp function available
- Medium: hydraulic oil, with medium separation e.g. diesel test oil from Shell 1404 V-Oil
- Ventilation: additional test oil pump
High dynamical pressure test unit for elastic specimens
A further project in this field was a high dynamical pressure test unit – hydraulic pressure adjustable up to 80 bar, frequency up to 25 Hz, optionally prepared up to 100 Hz. The specific feature in this case was the very high elasticity of the specimens.
The dynamical pressure pulsation unit PRO80HY is used e.g. for the life test of different components in the fuel supply of vehicles. The unit is suitable for test mediums like petrol, petrol substitutes, diesel or bio diesel. The tests are performed in a temperature chamber which is integrated in the test unit. Further a nitrogen inerting is included and the complete unit is certified according to ATEX standards.
Don´t hesitate to contact us for more details. We remain at your attention for any questions that may arise and would be pleased to assist you with finding the convenient solution for your requirements.
Please contact us for further information!