2 Making Measurements
Using Auto-diode for Diode Tests (U1272A only)
84 U1271A/U1272A User’s Guide
Using Auto-diode for Diode Tests (U1272A only)
The auto- diode function will help you test both forward bias
and reverse bias directions simultaneously. You do not need
to change the measuring direction to identify the diode’s
status.
1 Rotate the multimeter’s rotary switch to and set up
your multimeter as shown in Figure 2- 21.
2 Press to activate the auto- diode function (Auto ).
The primary display shows the forward bias voltage value.
The reverse bias voltage value is shown in the secondary
display.
• is shown briefly (along with a single beep) on the
secondary display if the diode is in a good condition.
• is shown briefly (along with two beeps) if the
diode is out of the thresholds.
Table 2-2 Auto-diode voltage thresholds
Forward voltage Reverse voltage Diode status
Primary display Secondary display Good No Good
OL or <0.3 V or >0.8 V –OL or >–0.3 V or <–0.8 V ✘
Within 0.3 V to 0.8 V –OL ✔
OL Within –0.3 V to –0.8 V ✔
The open condition will not be alerted as OL on both directions if the
auto-diode function is used.