Mercedes of the S-class W202

1993-2000 of release

Repair and operation of the car

Mercedes W202
+ 1.2. General information
+ 2. Maintenance
+ 3. Engines
+ 4. Lubrication system
+ 5. Cooling system
+ 6. Heating, ventilation
+ 7. System of ignition
+ 8. Fuel system
+ 9. Transmission
+ 10. Running gear
+ 11. Steering
+ 12. Brake system
+ 13. Body
- 14. Electric equipment
   14.1.2. Measuring devices
   14.1.3. Technology of measurements
   14.1.4. Checks of electric equipment
   14.1.5. Sound signal
   14.1.6. Replacements of safety locks
   + 14.1.7. Rechargeable battery
   + 14.1.8. Generator
   + 14.1.9. Starter
   14.1.10. Traction relay
   + 14.1.11. System of lighting
   14.1.12. Devices
   14.1.13. Dashboard
   14.1.14. Glow lamps on the dashboard
   14.1.15. Light switch
   14.1.16. Radio receiver
   + 14.1.17. Antenna
   14.1.18. Loudspeakers
   + 14.1.19. Rubber brushes of screen wipers
   14.1.20. Windscreen washer jets
   14.1.21. The washing nozzles of headlights
   14.1.22. Screen wiper and its engine
   14.1.23. Protect the car
   14.1.24. Anticreeping "immunodeficiency"
   14.1.25. Why headlights grow dull
   14.1.26. Galogenka
+ 14.2. Electrical circuitries

14.1.2. Measuring devices


For measurement of electric parameters in an onboard chain on sale there are so-called combined measuring devices which in one device unite the voltmeter for voltage measurement, the ampermeter for measurement of current and an ohmmeter for measurement of resistance.

The measuring devices which are available on sale differ among themselves mainly with the range and accuracy of measurements. Is established by the range of measurement in what area there have to be registered tension and resistance.

For motorists there are combined measuring devices which are specially intended for holding examinations in the car. By means of such device it is possible to measure the frequency of rotation of a shaft in the car, a corner of the closed condition of contacts of the breaker of system of ignition and tension up to 20 Century.

At measurement of resistance the device is, as a rule, limited to range in kilohms, In addition to it measuring devices are used to check of electric and electronic elements of a design. They allow to take broad measurement from small resistance in Ohms up to megaomny range. It is very precisely possible to measure tension (V) that first of all is required for check of electronic elements of a design.

If it is only necessary to check whether tension (V) moves in general, then the simple control bulb for this purpose approaches (And). However, it is valid only for those electric chains in which there are no electronic details. Nevertheless electronic details extremely sensitively react to too high currents. Under certain circumstances they can fail even at connection of a control bulb.


When checking electronic details (transistors, diodes and the operating knots) it is necessary to use the high-resistance indicator of tension (In). It works as well as a control bulb, however without damage of electronic elements of a design, and is suitable for carrying out all control operations.