Avtron Model T477W Bonding Meter
with B14703 Battery Pack Replacement Instructions
Part Number T477WC15292
Operating Instructions
Subject to the EAR, ECCN [9E610.a].
This information is subject to the export control laws of the United States, specifically including the Export Administration Regulations (EAR),
15 C.F.R. Part 730 et. seq. Transfer, retransfer, or disclosure of this data by any means to a non-U.S. person (individual or company), whether in the United States or abroad, without any
required export license or other approval from the U.S. Government is prohibited, including without limitation any diversion to a military end user or use in a military end use application.
2-5
2.10
Meter Operation
Select one of the five probes and connect it to the front panel J1. In making a measurement, make sure that the probe tips
penetrate any non-conductive film that may be present (and there are no flashing decimal points or erratic digits flickering in the
display). The accuracy is known only when the meter reading is
positive
. Momentarily press the TEST button located on the
front panel. The TEST button not only turns on the display but also changes the meter range. The first TEST button activation
causes the meter to operate at the 2 milliohm range. Subsequent activations of the TEST button will change the range from 2 to
20 to 200 to 2000 and back to 2 milliohms. The decimal point is automatically positioned for each range.
In order to conserve battery power, a built-in timer automatically shuts off the display after 52 seconds of operation. The
display may be illuminated by pressing the LAMP button located on the front panel. Meter range is not affected by the lamp
button; however, meter shutdown timing is delayed while the lamp button is activated.
2.11
Leading “1” Display
A leading “1” display indicates an over-range condition. If the display indicates a leading 1 (as in Figure 3), press the test
button once to advance to the next highest range. If the meter is over-ranging in the 2000 milliohm range, then the unknown
resistance is greater than 1999 milliohms and is out of the range of the Bonding Meter.
2.12
Erratic Digits
Erratic digits (erratic numbers flickering in the display) are an indication that the voltage sense connections are open or a large
over-range condition exists. Ensure that the voltage sense probes are making a good, low resistance connection. Advance the
range using the test button if necessary.
2.13
Flashing Decimal Points
Flashing decimal points are an indication that the resistance of the path formed by the current probes is excessive. This is
most common in the 2 milliohm range. The 2 milliohm range requires a current probe path of less than 200 milliohms.
Ensure that the current probes are making a good, low resistance connection.
1.___
Overrange on the 2 milliohm range
1_.__
Overrange on the 20 milliohm range
1__._
Overrange on the 200 milliohm range
1____
Overrange on the 2000 milliohm range
Figure 2-3.
Flashing Decimal Points
