The photon counter board is used to count the intensity count coming from the PMT.

The DB9 Connector going from the PMT to the photon counter board

Note:

• Pin 1/6 a twisted pair
• Pin 2/3 is a twisted pair
• Pin 2/3 twisted pair is the only signal wire that is actually used for counting, Pin 1/6 is not used

Materials Required

• Oscilloscope
• Signal Generator
• Testing Jig (Optional, but see below)

Test Jig
The test jig can be made with a male to female DB9 connector with pin 1, 2, 3, 5 and 6 connected (1/6, 2/3 should be a twisted pair). Pin 2 and 3 should be easily disconnected with something like a wago or a terminal strip.
Example of test jig Testing

1. Turn off the brewer
2. Install the test jig between the the PMT and the photon counter board with pin 2/3 disconnected
3. Turn the brewer on and start the software
4. Enter MM
5. run R,0,7,4;o. Since there is no signals, you should be getting 0's across the board.
6. With a signal generator, inject a 3.8VDC square wave at 10KHz onto pin 3
7. run R,0,7,4;o. You should be getting about 13,000 counts across all 7 slits.

Expected Oscilloscope Views