{"id":1150,"date":"2012-10-28T22:03:15","date_gmt":"2012-10-28T14:03:15","guid":{"rendered":"http:\/\/gergely.imreh.net\/blog\/?p=1150"},"modified":"2012-10-28T22:04:32","modified_gmt":"2012-10-28T14:04:32","slug":"laboratory-2-0-a-monitoring-system","status":"publish","type":"post","link":"https:\/\/gergely.imreh.net\/blog\/2012\/10\/laboratory-2-0-a-monitoring-system\/","title":{"rendered":"Laboratory 2.0 – a monitoring system"},"content":{"rendered":"

Looks like that one of my specialty as a physicist, and contribution to the labs where I have worked so far, is bringing different kinds of programming techniques, and technologies to the table. I’m not saying I’m any better than many of the professors, post-docs, and students I’ve met so far (there are plenty of ingenious ones), it’s more like I experiment with different tools, have tried more of the cutting edge or recent technologies, did some web programming and could whip up something quick – that might not work very well at first, but does broaden the horizon for the rest of the people.<\/p>\n

Also, I’m a lazy person, so want to automate as much as possible. That was on my mind recently when we have been preparing to do a vacuum-system\u00a0bake-out<\/a>. It’s essentially a procedure to have a delicate experimental system, mostly made up of steel, glass, and stuff like that, closed up from the atmosphere, all the air pumped out, then heated up to high temperature (~150-300\u00b0C). One has to be careful, because things can break, there are temperature limitations for some materials, also on how quickly that temperature can change, requiring careful monitoring of the status of the system. And the whole thing takes something like two weeks or more.\u00a0Perfect setting for automation.<\/p>\n

Set up the electronics<\/h2>\n

The pressure measurements are done by some expensive other equipment so didn’t have to bother with that one yet, so set to work first on the temperature monitoring. Before it was a bunch of thermocouples<\/a> and multimeters<\/a>, requiring manual intervention and lots of labour. Instead, got some inspiration from Adafruit’s Thermocouple Breakout Board<\/a>, using the MAX31855<\/a> chip, and also from the Thermocouple Multiplexer Shield<\/a>. It can handle only one channel, but can use some other chip together with it to switch between the different thermocouples, and so we can read it out one-by-one. The Adafruit board could only handle 1 channel, and the multiplexer shield was using an older chip for the measurement that I could not buy anymore. In the end, found a good analog multiplexer that one that is sold in the computer market here in Taipei, the CD4067B<\/a>, and it works pretty well.<\/p>\n

\"Breadboard<\/a>
Breadboard setup for temperature monitoring with Arduino<\/figcaption><\/figure>\n

Of course, setting it all up was quite a bit of fun times, as there were way too many gotchas along the way.<\/p>\n