Custom Probe for MI Model 904 Gaussmeter

[enut11]

I have a Magnetic Instrumentation (MI) model 904 Gaussmeter that came without a probe and would like to get it working.

Have not been able to find any info or manual online.

I believe this type of instrument uses a Hall Effect chip. These chips normally have 3 pins: power, ground and output.

You can see from the photos that the probe socket has 4 wires so maybe the fourth is a shield.

Our local supplier (Jaycar) has a UGN3503U sensor that I will try. It needs a nominal 5v supply.

Ebay has the following linear chips on offer:
https://www.ebay.com.au/itm/10-PCS-AH49E-TO-92S-AH-49E-LINEAR-HALL-EFFECT-IC/122490059728
https://www.ebay.com.au/itm/4PCS-HAL401SF-A-Encapsulation-SOT89-3-Linear-Hall-Effect-Sensor-IC/372247259357

I have never used a Hall chip so any feedback from the Forum would be appreciated.

**NOTE: This thread is now in the PROJECTS section **