Signal conditioning boards for Thermocouple Amplifier

http://www.embeddedtronics.com/signal.html

Schematic

Layout

Parts list

sample rate, scan rate

sample rate = how many samples per channel per second
scan rate = how many scans per second

Example:

4 channels ( ch 0,1,2,3 )
take sample rate = 250 samples / channel / second, it means 1000 samples / second
take scan rate = 250 scans / second, it means 1 scan = 4 mlliseconds

Illustration for interval scanning:

Scan | Channel | Time (microseconds)
-------------------------------------
0 0 0
0 1 1
0 2 2
0 3 3
-------------------------------------
1 0 4000 (4 milliseconds)
1 1 4001
1 2 4002
1 3 4003
-------------------------------------
2 0 8000 (8 milliseconds)
2 1 8001
2 2 8002
2 3 8003
-------------------------------------

sensor is coming

The sensor from Vereta is finally coming. Surprisingly, they send us two thermocouples type K. One is called as active sensor which measures the perceived temperature and another is the passive sensor only measures operative temperature.

To get the perceived temperature, we must provide another temperature sensor that sense the temperature of ADDA card. Now we are using IC: TMP01

And the equation for perceived temperature will be :
GT = ((Temp_active - Temp_card ) - 13.00) * 1.05) + Temp_card

Equation for the air velocity (m/s) is
v = ((Temp_passive - Temp_active)+ 14.4)*0.06
ps : the output is not linear, = 0.4 at 0.4 m/s

Piezo Film Pulse Sensor

I just realized that none of the pulse watch that we had discussed weeks ago measures the pulse from wrist. Both from Polar and Sigma Sport always use the chest strap to take the EKG signal and send it to the watch. And this is not what we want.
Our ideal pulse watch should look like a normal watch, that sense the pulse from the inner part of wrist. Unfortunately, this kind of watch is only available as blood pressure unit.

I found an interesting experiment from internet, the project name is Piezo Film Pulse Sensor. A simple piezo film detects pulse-caused skin movement, and the output signal (EKG like) can be used directly to count pulses over a period of time. The project description is here.

The next day, one of my supervisor bought a pulse watch from Tchibo. He was thinking about not using the strap on chest but at wrist. I tried to place it here and there, but the strap didn't recognize any signal if you put it at wrist.

Then came an idea to use the strap after all, but not the watch. Based on experience of another AmI project, they simply took the radio freq. receiver circuit from the watch, the circuit provides the pulse signal as output.

So, now I can forget about making my own Pulse Sensor and use the Tchibo pulse watch instead.