12 • 35-3001A-01-XX1 Sample-Draw Detector Operator’s Manual
Zero Pot
The zero pot is located in the upper right corner of the amplifier (see Figure 3). Use a small
flat blade screwdriver to turn the zero pot’s adjustment screw and adjust the amplifier’s zero
(fresh air) output during the start-up and calibration procedures. Turn the adjustment screw
clockwise to increase the fresh air output and counterclockwise to decrease the fresh air
output.
Span Pot
The span pot is located below the zero pot (see Figure 3). Use a small flat blade screwdriver to
turn the span pot’s adjustment screw and adjust the amplifier’s gas response output during the
calibration procedure. Turn the adjustment screw clockwise to increase the span output and
counterclockwise to decrease the span output.
CAUTION:
The amplifier includes additional pots. They are factory-set. Do not adjust
them.
Controller and Detector Terminal Strips
The controller terminal strip and detector terminal strip are three- and four-position plug-in
style terminal strips, respectively. The controller terminal strip is located on the right side of
the amplifier and the detector terminal strip is to the left of it. Both terminal strips are factory
wired to the sensor and main circuit board.
Test Points
The test points are on the left side of the amplifier (see Figure 3). The test points produce a
100 mV to 500 mV output that corresponds to the sample-draw detector’s 4 to 20 mA output.
Use the test points and a voltmeter to measure the amplifier’s output during the start-up and
calibration procedures. The black test point in the upper left corner is the negative (-) test
point and the red test point to the left of the zero and span pots is the positive (+) test point.
Installation
This section describes procedures to mount the sample-draw detector in the monitoring
environment and wire the sample-draw detector to a controller.
Mounting the Sample-Draw Detector
1. Select the mounting site. Consider the following when you select the mounting site:
•
Is there enough room to open the housing door and make wiring and tubing
connections at the bottom of the housing?
•
Make sure there is sufficient room to perform start-up, maintenance, and calibration
procedures.
•
Are the flowmeter and status LEDs visible?
