AIR TECHNIQUES INTERNATIONAL
A Division of Hamilton Associates, Inc.
11403 Cronridge Drive
Owings Mills, MD 21117-2247 USA
Tel 410.363.9696
Fax 410.363.9695
http://www.atitest.com
2H AMPLIFIER LINEARITY CHECK
U S I N G A P I C O A M P E R E S O U R C E
Page 1 of 2 PCL-103-WI Rev B 19-July-2011
Use only the equipment specified:
Keithley 6220 picoampere current source
NOTE:
The following procedure is intended for ATI-2H units that have
previously had Internal Reference values stored in battery-backed RAM.
Procedure:
1. Be sure that both the picoampere source and the 2H unit are powered down.
2. Switch on the picoampere source. Ensure the blue output LED indicates an OFF (disabled)
state.
3. Switch on the power to the 2H unit. The unit will briefly sound an audible tone, display the
software version and start scanning.
4.
The LED on the “REF” button should start blinking.
5.
Press the “ENTER” button and the stored Reference reagent value (DOP, PAO, User or High)
will be displayed on the %Leakage display. Use the
or
key to change the selection to PAO.
6.
Press the “ENTER” button again and “100” will be displayed on the %Leakage display.
7.
Press the “ENTER” button again. After scanning the LED over the “0” key should begin
flashing.
8.
Press “ENTER” button again. The 2H unit will scan for approximately 10 seconds and display
all zeros on the %Leakage display.
9. Disconnect phototube signal from signal connector labeled J2 on the 2H unit main PCBA and
connect the output of the picoampere source to J2.
10. Set the picoampere source to -08.000 µA (-0.80 X 10
-5
amperes) and enable the signal output.
11. Press the
“100” key and the “ENTER” button sequentially. The unit will begin scanning. When
complete, the LED over the
“0” key will begin flashing.
12. Disable the picoampere source signal output.
13.
Press “ENTER” button on the 2H. The 2H unit will start scanning. When complete, the 2H %
Leakage display should show “0.0000” and an audible tone will sound.
14. Enable the picoampere source signal output.
15.
The 2H % Leakage display should show “100.00”. (Tolerance: -0.80 ± .02 x 10
-5
amperes).
Record the picoampere source reading on the calibration report of the UUT.
NOTE: Leave the picoampere source output enabled for the following steps until
instructed otherwise.