I am running a feasibility study on a scuba tank pressure monitor.
Essentially, I'd like to log the pressure profile of a tank throughout a dive by measuring it with a pressure transducer connected to one of the regulator first stage's high pressure ports.
I've been looking around for pressure transducers that can handle pressures up to 250 bar / 3,600 psi (tanks are usually filled up to 200 bar / 3,000 psi), but I've only found really expensive and pretty bulky ones - a few examples: http://www.astsensors.com/sensors/AST4000 , http://uk.rs-online.com/web/p/pressure-sensors/7970962/ ).
Now, most scuba gear manufacturers now sell wireless pressure transmitters that read the pressure and send it to a dive computer (for example http://www.suunto.com/Products/Dive-Accessories/Suunto-wireless-tank-pressure-transmitter-led/ ). I have opened one and it seems like they have a much smaller transducer inside, probably about 1 cm tall. Plus, I doubt they'd use a £100/$150 component inside their transmitters.
Am I looking at the wrong sort of transducers? Do you have any suggestions on which ones could I use? Ideally, I was looking for something in the £30-50/$50-80 range.
Thank you very much! Nick