SRS Ion Gauges

SRS Ion Gauges

Setting up a new Ion Gauge

Several parameter need to be adjusted from the default value when a new SRS Ion Gauge is installed. From the main Pressure summary screen, tap on Gauges, then IG1. The following is the adjusted parameters:

  • N2 Sense Factor: 25

  • Gas Correction Factor: 1

Then select Advanced. Set the following parameters:

  • Emission Current: 4 mA

  • Degas Time: 5:00

  • Degas Power: 1 W

Degassing the Ion Gauge

  • Under Construction

Replacing LED Backlight

  • From Wistey

  • Replacing with LEDs isn't much harder than the CFL:

  1. Order one of these, $10: http://www.ledsupply.com/led-drivers/bucktoot-150ma-constant-current-led-driver (I might go for a lower 100-120mA if I could find one.)

  2. Order one of these, $29: https://davandisplay.com/catalog/product/KIT10-12LED-SINGLE . They're designed to be cut to length. The SRS bulb is 100-110mm long.

    1. (Or buy a 4 pack for $49: https://davandisplay.com/catalog/product/KIT10-12LED-QUAD)

  3. Both come with a current driver circuit that you don't need (wrong volts & amps). Cut the wires near the current driver and discard it.

  4. Using a Dremel or xacto, cut the LED stick to length, removing LEDs in a multiple of 3. Cut minimally so the circuitboard is intact near the first remaining LED.

  5. The current driver in #1 has two input wires (red/black) and orange/green wires output. Solder orange to LED+, green to LED-.

  6. Crimp the red & black wires onto either the 20V or 24V internal power supply wires in the SRS. (I used spade terminals so I can remove them easily later.)

  7. If necessary, use kapton tape to tape the LEDs to the edge of the backlight diffuser plate. Reassemble and bask in the long-lived glow.

Misc