Autoclave

I need to find a way to measure temperature and pressure from inside of an autoclave. The first challenge will be finding sensors that can withstand that environment. The second challenge is how to get the signal out from the inside of the chamber.

Any suggestions?

I need to find a way to measure temperature and pressure from inside of an autoclave.

What is an autoclave?

The first challenge will be finding sensors that can withstand that environment.

Describe the environment - airtight I assume. - temp - humidity - pressure - acidity - etc..

The second challenge is how to get the signal out from the inside of the chamber.

  • wire
  • optical e.g. an IR LED
  • ..

You can also place mechanical sensors in the box and use a webcam before a window and do image analysis/comparison.

Autoclave : http://en.wikipedia.org/wiki/Autoclave

I would use a thermocouple for temperature.
You might need a thermocouple shield or an ic.

A NTC (temperature resistor) is also possible, this can be connected directly to the Arduino, but it is less accurate.

For the pressure, you probably need an industry strength pressure sensor.

To measure the temperature, there is a Maximum Registering Thermometer avaialable. You simply place it inside the autoclave and run a cycle. It will record the highest temperature reached

Hope this helps

Wally

Has anybody autoclaved an arduino? I want to use arduinos in cell culture equipent and would like to know if the mega32u4 can withstand dozens of cycles of 2atm/121°C.

cheers

tim

Well, since the 32U4 used on the board is only rated to 85C, and who knows about the other parts, it's probably not a good idea. A higher temperature rated part is not available. You can however get automotive rated Atmega328P, good to 125C, http://www.digikey.com/product-detail/en/atmel/ATMEGA328P-15AZ/ATMEGA328P-15AZCT-ND/2477177 and other 150C rated parts and come up with a board that can handle the extremes. I did a design like that to use in vehicles in Africa. You'd want to conformal coat the board as well to keep any moisture from condensing on it.

Only the probes need to be autoclaved. They could be reattached afterward as long as they stay sterile. I was thinking about setting something like this up for my fermenter.

Jim

Professional sensors mount "through the wall", so that only the sensors reside in the (possibly aggressive) environment inside an autoclave, with all cabling outside it. For temperature you can use encapsulated thermocouples.