Vorel 81784 карманный [5/6] O p e r a t i n g m a n u a l

OPERATING MANUAL

seen if the measurement leads of the meter are short-circuited.

Measurement of capacitance

Switch the range selector to the position of the measurement of capacitance. Make sure the capacitor was discharged

before the measurement. Do not ever measure the capacitance of a charged capacitor, since it might damage

the meter and cause an electric shock.

Measurements of frequency

Connect the measurement cables to the sockets marked as „VΩ” and „COM”; switch the range selector to the posi-

tion of measurement of frequency. Put the measurements leads to the terminals of the tested element and read the

result of the measurement in the display. Do not ever measure the frequency of a signal whose frequency exceeds

250V RMS (average value). The measured signal should not exceed 100V RMS, since otherwise the result cannot

be read.

Measurement of temperature

Connect the special cable to the TEMP socket and observe the polarization of the terminals. Switch the range selector

to the position of measurements of temperature. Measure the temperature with the other end of the thermoelement.

The meter will indicate the temperature in degrees centigrade. The thermoelement supplied with the device permits to

realise measurements only up to 250

C. Measurements up to 300

C are permitted provided the duration of measure-

ments is short.

Diode and conductivity test

Connect the measurement cables to the sockets marked as „VΩ” and „COM”, and switch the selector to the diode

symbol. Place the measurement leads at the diode terminals in the conduction direction and the reverse direction. If

the diode is functioning correctly, then at the diode connected in the forward direction we will read the voltage drop for

this diode expressed in mV. In case the diode is connected in the reverse direction the display will read „1”. If the diode

terminal is damaged the display will read „0” independently of the direction in which the diode is connected. Correctly

functioning diodes show a low resistance in the forward direction and a high resistance in the reverse direction. It is

strictly prohibited to test live diodes.

In case the meter is used for conduction measurements, the internal buzzer will emit sound each time the measured

resistance drops below 30±10Ω.

Transistor test

Switch the measurement range selector to the position marked with the h

symbol (measurement of the gain coef-

ficient of the transistor). Depending on the type of transistor it must be connected to the socket of the base marked

as PNP or NPN, making sure the terminals of the transistor are placed in accordance with the letter indications: E

- emitter, B - base, C - collector. If the transistor is functioning properly and the connection is correct, the result of the

measurement of the gain coefficient is read in the display. It is strictly prohibited to test live transistors.