I would like to build my own thermofilter. I have a couple of questions. Any help is appreciated.

1. the portafilter is brass- I am assuming people are soldering the thermocouple in place so it doesnt leak at 9 bars? What measures are taken to protect the the insulation on the wires while soldering? Any tips on getting this portion done correctly would be awesome.

2. What type of thermocouple is best? Any pointers on where to buy?

3. I understand people use Fluke testers- is there any particular model people use?

4. I also read on others people try to mimic the puck by adding a sponge to slow the flow to 2.5 oz for 25-30 seconds or so.. The extra half ounce being the water absorbed by the coffee inside the portafilter. I also read getting this flowrate by adding a sponge for backpressure can be tricky. Can't a needle valve be used to dial in the flow rate to exactly what you want and have a high pressure tube cut the exact length so its volume is equal to exactly one half ounce? Does this achieve the same result, but also add a little more flexibility?

I have drawn what I feel would be relatively easy to build. Any criticism and or feedback is greatly appreciated. Thanks

Ltrain5000 wrote:I would like to build my own thermofilter.

From the FAQ: DIY Thermofilter Build. But keep in mind that the raison d'être of a Scace thermofilter is adherence to a standard. The various DIY approaches documented in the forums are certainly valid ways of measuring temperature for your specific use, but your measurements probably won't match that of others using a Scace thermofilter.