720A Operation and Maintenance Manual – Rev S – January 25, 2019
Page 9
13231 Rooster Springs Rd.,
Austin, TX 78737
T:
(512) 858-4045
E:
amptec.com
SECTION D: OPERATION, FEATURES, AND USE
D-1 General Use Information
The AMPTEC 720A is a micro-ohmmeter designed to accurately measure low level DC
resistance from 200 m
Ω
to 200 K
Ω
. The 720A meter may be used immediately after the
unit has been turned on and been given a fifteen (15) minute warm up period
(temperature range limits permitting).
To use the 720A meter to make a resistance measurement, first connect the desired
measurement leads to the appropriately colored banana jack terminals on the unit’s
front panel. If your unit does not have the autorange feature, select your desired range
by pressing in the push button switch that matches the value needed. If your unit has
the autorange feature, you may select your desired range manually or press in the push
button switch below “AUTO” and the unit will automatically select the appropriate range
when it takes a measurement.
Next, place the measurement leads/probes across the unknown resistance value that
needs to be measured. At this point, the 720A meter should start updating the LED
display once an electrical connection has been made. If your 720A is using the
autorange feature, one of the three LEDs to the right of the display should indicate the
unit of measurement being shown (either mΩ, Ω, or KΩ). Once
the measurement leads
are removed from the component that was being tested, the meter will wipe the
resistance reading from the display.
If you have any other general use questions, please contact AMPTEC.
D-2 Front Panel Features
Sub-sections D-2.1 through D-2.6 provide information on the features, design, and uses
of the 720A meter’s front panel. The below photo (
Figure 1
) shows the details of a
commercial 720A front panel. The key to the right of the front panel highlights the main
features that will be described further in this section.
KEY
1
On/Off Switch
2
Range Switches
3
Display
4
Banana Jack
Terminals
Figure 1
Commercial Version of 720A Front Panel
