S-class W202 Mercedes

1993-2000 of release

Repair and car operation

W202 Mercedes
+ 1.2. General information
+ 2. Maintenance
+ 3. Engines
+ 4. Greasing system
+ 5. Cooling system
+ 6. Heating, ventilation
+ 7. Ignition system
+ 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. Equipment of measurements
   14.1.4. Electric equipment checks
   14.1.5. Sound signal
   14.1.6. Replacements of safety locks
   + 14.1.7. Storage battery
   + 14.1.8. Generator
   + 14.1.9. Starter
   14.1.10. Traction relay
   + 14.1.11. Lighting system
   14.1.12. Devices
   14.1.13. Dashboard
   14.1.14. Filament lamps on the dashboard
   14.1.15. Light switch
   14.1.16. Radio receiver
   + 14.1.17. Aerial
   14.1.18. Loudspeakers
   + 14.1.19. Rubber brushes of screen wipers
   14.1.20. Jets of a stekloomyvatel
   14.1.21. 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. "Galogenki"
+ 14.2. Electroschemes

b47c026d b47c026d

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 tension measurement, the ampermeter for measurement of a current and an ohmmeter for resistance measurement.

Measuring devices available on sale differ among themselves mainly with a range and accuracy of measurements. By a range of measurement it is established, in what area there should be traceable tension and resistance.

For motorists there are combined measuring devices which are specially intended for carrying out examinations in the car. By means of such device it is possible to measure 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 till 20 Century.

At resistance measurement the device is, as a rule, limited to a range in килоОмах, In addition to it measuring devices are applied to check of electric and electronic elements of a design. They allow to carry out wide measurement from small resistance in Ohms up to a megaomny range. Very precisely it is possible to measure tension (In) that first of all it is required for check of electronic elements of a design.

If it is necessary to check only, whether tension (V) moves in general, 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.


At check of electronic details (transistors, diodes and operating knots) it is necessary to apply 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.