The spark plug tightness measurement system has been used for many years at the customer’s site. With a view to expanding production to other countries, a mechanical basis for new systems was produced in the customer’s development workshops. Compared to the current state, the system has been modified so that there is a computer with measuring technology in the switchboard, and in addition central stop is added. Central stop works by pushing the cups and turning off the heater when pressed, but keeps the computer running.


Use of measurement program should not change, but the following set of program modifications was required:

  • Adaptation to the above change to the central stop operation.
  • Possibility to recall the measured sample data on the screen and print them directly in the same format as from running measurement.
  • Export data from individual measurements to xls / csv / pdf.
  • Selection of data for export according to entered criteria – date, name, program, test result.
  • Modification of the control screen – constant overview of the set parameters of the program (temperature, test duration – eg 5min, 60min, etc., allowed air leak – eg 2ccm, 0.6ccm, etc.)
  • Bulk Insert – import test program settings from TXT.
  • Possibility to set maximum pressure leak not only according to 2 standards, but also the third option, where the maximum allowable pressure leak would be adjustable, via password.
  • Improve the comfort of entering new plug types and parameters into the program and deleting them without having to start the measurement.
  • Language versions of the control program (libraries with a dictionary, currently using Russian).

The most advantageous solution to the problem is to use a measuring technique connected to the computer via USB. This solution completely eliminates the dependence of measuring technology on computer and vice versa and allows any part of the measuring chain to be replaced with another (new) if necessary. LabJack U6 measuring module is used (see picture). It is placed directly into the existing switchboard. This way it is protected from environmental influences and possible theft. It is equipped with 14 common ground inputs, of which 11 are used for measurement. It is also equipped with 20 digital inputs and outputs, of which only a part is used. The module is powered directly from the USB bus. The control computer is also located in the switchboard. An office computer with a 19-inch monitor and a wireless mouse and keyboard was used. These components are also standard.


The subject of delivery are further modules for signal processing and sensors, as follows:

  • Pressure: DMP311 / 160kPa pressure sensor,
  • temperature: Pt100 temperature sensors,
  • switchboard with measuring technology and signal conditioning circuits.

On the occasion of investment in measuring program modifications, it has proved advantageous to invest in re-creating the same measuring program in 64-bit Windows environments. Specifically, it is created now in Lazarus environment, which suits for programs running in both Windows and Linux environments. At the same time it is freeware so that any modifications to the program can be made by the customer’s staff without need to spend for license. In order to minimize costs and keep the created program as much as possible with what the staff is accustomed to, the objects from which the original program is composed were created in the Lazarus environment. Then the measuring program was rebuilt from the created objects so that it is as close as possible to the original one.

More information request here.