[cmjones01]

Thank you for the ideas. The hacksaw blade should help. That eevblog thread is great because it shows pictures of what's inside, so I know what I'm cutting round. Time to start digging.

I'm also toying with the idea of putting another sensor in there for monitoring the oven temperature. If it's not sacrilege, a digital temperature sensor and a microcontroller should be able to generate a signal at a frequency related to the temperature - 10Hz per degree C, or similar. Then the counter could read out its own oven temperature, which would be a useful confidence check in the future.

Chris