Fluke 8846A User Manual

8845A/8846A
Users Manual
4-16
Function modifiers:
None
Checking Diodes
The diode function sends a current through a semiconductor junction while the Meter
measures the voltage drop across the junction (or junctions). Measurements are displayed
in the 10 V range at a relatively fast measurement rate. "OPEN" is displayed for voltages
10 % above the compliance voltage setting. Typical junction voltage drop on good
junctions are 0.3 to 0.8 volts. If enabled, the beeper will make a short beep when a good
junction is detected. Shorted diodes will indicate a significantly lower voltage.
With the higher compliance voltage (up to 10 V), the Meter’s diode test function can test
zeners up to 10 volts, diode stacks and LEDs. The selectable current and maximum
voltage allows you to tailor the diode test to the expected voltage for the junction being
tested.
To check a diode:
1. Press S twice on the 8846A or D once on the 8845A. An example of the diode
test display is shown below.
0.5994
F1 F2 F3 F4 F5
+
caw13f.eps
2. Select the test voltage and current appropriate for the diode being tested by pressing
the associated soft keys.
3. Connect the test leads as shown in Figure 4-8.
2
INPUT SENSE
HI
LO
FRONT
REAR
10 A
1V
00
mA
4 W
HI
LO
2W/4W
V
300V
FUSED
1000 V CAT I
600V CAT II
4
caw024.eps
Figure 4-8. Diode Testing Connections

Fluke 8846A Specifications

General

Frequency Range	3 Hz to 300 kHz
DC Voltage Range	100 mV to 1000 V
AC Voltage Range	100 mV to 750 V
Resistance Range	10 Ω to 1 GΩ
Continuity	Yes
Diode Test	Yes
Temperature Measurement	Yes
Display	5.5 digit
Connectivity	USB, RS-232, GPIB
DC Current Range	100 µA to 10 A
AC Current Range	100 µA to 10 A
Frequency Accuracy	0.01 %
Capacitance Range	1 nF to 100 µF
Display Type	VFD
Power Supply	100 V to 240 V
AC Voltage Accuracy	±(0.06% + 0.03% of reading)
Resistance Accuracy	±(0.01% + 0.001% of reading)