KYORITSU 1109S User Manual

Page 22

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6-8. Terminal Current LI, Terminal Voltage LV &Diode Test

# CAUTION
Do not measure the internal resistance of a diode with low reverse
withstand voltage using x 10kΩ range. The 12V voltage to be
applied at this test could damage the diode. Check the rating of a
diode before testing.

⑴ Current flowing across the −COM terminal and + terminal during

resistance measurements is indicated as LI. When LI flows into the

circuit under test there occurs a voltage drop. This is defined as LV.

Use the scale marked LI and LV for reading terminal current and

voltage. Circuit impedance may change according to the current that

flows into the circuit being measured or the voltage applied to the

circuit. Also, an abnormal condition may develope in the circuit due to

its self heating. Therefore, make resistance measurements at each

range w.ith the above in full consideration

Shown below are the values of terminal current

and voltage on each resistance range: Table 3

Resistance

Range

X10

X1k

X10k

Multiply by

Direct Reading

Max. Terminal

Current LI

150mA

15mA

150μA

60μA

Max. Terminal

Voltage LV

12V

⑵ If the connection to the circuit is made as shown in Fig. 4, it is

possible to measure the forward current IF or reverse current I

of a

diode using the LI scale. It is also possible to measure the forward

voltage V

or backward voltage V

of a diode using the LV scale (Fig.

4).

⑶ As described for the resistance measurements, make the ohm zero

adjustment after every change of the measuring range.