-17-
RESISTANCE MEASUREMENTS
1) Connect the black test lead to the “COM” terminal.
2) Connect the red test lead to the “V
Ω
MA” terminal.
3) Set the range switch to the desired “
Ω
” position.
4) If the resistance being measured is connected to a circuit, turn off the power to the circuit being tested and
discharge all of the capacitors.
5) Connect the leads across the resistor to be measured and read the display.
When measuring high
resistance, be sure not to contact adjacent points even if insulated. Some insulators have relatively low
resistance and will cause the measured resistance to be lower than the actual resistance.
DIODE CHECK
1) Connect the black test lead to the “COM” terminal.
2) Connect the red test lead to the “V
Ω
MA” terminal.
3) If the diode being measured is connected to a circuit, turn off all power to the circuit and discharge all
capacitors.
4) Set the range switch to “ ”.
Forward Voltage Check
5) Connect the red lead to the anode and the black lead to the cathode of the diode. Normally the forward
voltage drop of a good silicon diode reads between 450 and 900mV.
Reverse Voltage Check
6) Reverse the leads to the diode. If the diode is good, an overrange indication is given (a 1 in the most
significant digit and blanks in the remaining digits). If the diode is bad, “000” or some other value is
displayed.
h
FE
MEASUREMENTS
1) Set the range switch to h
FE
and insert the test transistor into the appropriate NPN or
PNP holes in the transistor socket.
2) Read the h
FE
of the transistor.
BATTERY & FUSE REPLACEMENT
If “ ” appears on the display, it indicates that the battery should be replaced.
To replace battery and fuse (250mA/250V), remove the 2 screws in the bottom of the case.
Simply remove the old fuse/battery and replace with a new fuse/battery.
QUIZ
1. The function of the A/D converter is to . . .
A) convert digital to analog.
B) divide the analog signal by 2.
C) convert analog to digital.
D) convert AC to DC.
2. The divider used for DC voltage measurements is a . . .
A) divide by 20.
B) capacitance divider.
C) divide by 5.
D) resistor divider.
3. When the AC voltage is measured, it is first . . .
A) divided by 2.
B) rectified.
C) divided by 100.
D) sent to a high pass filter.
4. When measuring current, the shunt resistors convert the
current to . . .
A) -0.199 to +0.199 volts.
B) -1.199 to +1.199 volts.
C) -0.099 to +0.099 volts.
D) -199 to +199 volts.
5. The DC voltage divider resistors add up to . . .
A) 100
Ω
.
B) 1000
Ω
.
C) 100k
Ω
.
D) 1M
Ω
.
Answer
s:
1.C
, 2.
D, 3.
B, 4.
A,
5.D
, 6.
A, 7.B
, 8.
C, 9.
B, 10.
B
6. Resistance measurements are made by . . .
A) comparing voltage drops in the unknown resistor and a
reference resistor.
B) measuring the current in the unknown resistor.
C) measuring the current in the reference resistor.
D) equalizing the voltage drops in the unknown and the
reference resistors.
7. The measurement cycle performed by the A/D converter can be
divided into time periods known as . . .
A) long and short.
B) autozero, integrate and read.
C) zero, read and interphase.
D) convert, integrate and display.
8. A resistor with the band colors green-black-green-brown-green is . . .
A) 50.5k
Ω
+5%.
B) 5.15k
Ω
+10%.
C) 5.05k
Ω
+.5%.
D) 5.05k
Ω
+1%.
9. The M-1005K has . . .
A) A 3 digit display.
B) A 3 1/2 digit display.
C) A 4 1/2 digit display.
D) None of the above.
10.When measuring 450mA, the meter leads should be connected to . . .
A) COM and V
Ω
mA.
B) COM and 10A.
C) 10A and V
Ω
mA.
D) COM and Building GND.
e
b
c
e
e
b
c
e
NPN PNP
+
