2.3. Test
Run
The battery pack inside the GT-321 should be charged for 15 hours prior to use (see
section 5.3 – Battery Pack). Once the battery pack is fully charged,
remove the rubber
cap
from the GT-321 inlet nozzle. The inlet nozzle protrudes from a hole in the top of
the GT-321 case.
Next, turn on the power switch that is located on the left side. The LCD display on the
GT-321 will indicate
0.3u.
If there is no display or a dim display the LCD contrast may
require adjustment (see section 5.6).
Press the
<SELECT>
key several times and note that the display sequences through
the particle size selections of
0.3u
,
0.5u
,
1.0u
,
2.0u
, and
5.0u
. Select the 0.3u size,
then hold the GT-321 with the inlet nozzle pointing upward.
Finally, press the
<START>
key. You should hear the internal vacuum pump start
running. After 9 seconds (subsequent readings every 6 seconds) a number will appear
on the display representing the number of particles per cubic foot larger than 0.3µm.
If the sample was taken in a relatively clean area the count may be as low as 200,000
whereas in a dusty area it could be as high as 3,000,000. The GT-321 will continue to
take 9 more 6-second samples. The results from the 10 samples are then averaged and
displayed.
This finishes the test run. Always remember to turn the power off when not in use to
conserve battery power.
The GT-321 is now checked out and ready for use, however, you should read the rest of
this manual to better understand how to use and maintain this instrument.
3. GT-321
Overview
3.1. Description
The GT-321 is designed to be a small, easy to use and completely portable hand-held
particle counter that can provide fast and accurate measurement of particulate
contamination in particles per cubic foot. The GT-321 has 5 selectable size ranges of
0.3, 0.5, 1, 2, and 5 micron.
The GT-321 contains a laser diode based sensor, NiCd battery pack, vacuum pump,
microprocessor electronics, LCD display and user input keys all in one small package.
The accuracy of the GT-321 is certified according to ASTM and JIS standards and
comparable to larger more expensive bench top particle counters. The fast 6-second
response of the GT-321 makes it especially useful for troubleshooting contamination
problems and tracing contamination leaks to the source.
The laser diode based sensor inside the GT-321 utilizes a specially designed elliptical
mirror for high light collection efficiency and improved signal to noise. Precision optics
GT-321-9800 Rev D.doc
GT-321 Operation Manual
Page 9 of 18
AC Tool Supply
877-207-1244
www.aikencolon.com
