720A Operation and Maintenance Manual – Rev S – January 25, 2019
Page 10
13231 Rooster Springs Rd.,
Austin, TX 78737
T:
(512) 858-4045
E:
amptec.com
The below photo (
Figure 2
) shows the details of the front panel of the NSN version of a
720A meter. There are a few key features which differ from the previous photo, and they
will be described further in this section.
D-2.1 On/Off Switch
This switch (refer to item 1 within
Figure 1
on the previous page) controls the power of
the unit. When flipped upwards, the unit is on and operational. When flipped
downwards, the unit is off and the only operation the unit can perform is the charging of
its batteries, if equipped with the 720-BAT option.
Once the switch has been flipped into the “on” position, the unit’s display should
immediately light up, indicating that the unit is on and operational. If the unit’s display
does not engage when the switch is flipped into the “on” position, check to ensure that
the unit’s AC power cord is properly inserted into both the unit’s rear panel and a power
outlet. If equipped with the 720-BAT option, this issue may indicate dead batteries,
which can be resolved by charging the unit’s batteries with the power supply provided
by AMPTEC.
If you have continued difficulty troubleshooting a unit that won’t operate when turned on,
contact AMPTEC for assistance.
D-2.2 Range Switches
These switches (refer to item 2 within
Figure 2
) control which range the unit is making
measurements in. The available ranges of measurement are as follows
: 200 mΩ, 2 Ω,
20 Ω, 200 Ω, 2 KΩ, 20 KΩ, and 200 KΩ. When one range button is pressed, all other
buttons should be fully extended. If this is not the case, then your range switches may
be broken, and you should contact AMPTEC for assistance.
If you attempt to take a measurement that is too high for the range you have selected,
the unit will enter overrange mode. This will be indicated by the display flashing four
zeros on the screen. The unit will automatically exit overrange mode if you press the
appropriate range switch for the measurement being taken. For more information on
how the overrange mode works, please visit section D-2.3.2 on the following page.
KEY
5
Autorange Button
6
Unit of Measurement
LEDs
Figure 2
NSN Version of 720A Front Panel
