The analyser functions surprisingly well. The differences to the Divesoft analyser that uses a different technology is within the measurement error of 1%, both for the oxygen as well as the helium content.
Biggest plus for me, is that this analyser is not sensitive to noise (as the Divesoft is) I can use it in the intake of my compressor (fed by a small pump) after my Trimix-Stick and double check what is going through the compressor, not having to rely only on the two oxygen sensors of the TMX stick
Bill of Materials: TMX_Analyser__StripBoard_R03_for PCB.fzz
Label | Part Type | |
He Sensor | MD62 | AliExpress Link |
O2 Sensor | Original CITY AO2 | AliExpress Link |
U1 | Voltage Regulator – Variable LM316 | AliExpress Link |
Seeduino | seeeduino-xiao | AliExpress Link |
ADS1115 | 16Bit I2C ADC | AliExpress Link |
Display | 1.3’’ OLED 128x64 | AliExpress Link |
Battery Capacity Indicator | 1S 3.7V li-ion 4.2V | AliExpress Link |
Battery Storage Box | 1x 18650 Battery holder | AliExpress Link |
Battery charging board | USB-C LiPo Charging board | AliExpress Link |
ON / OFF Switch | 2 pin ON/ OFF | AliExpress Link |
DC-DC Step Up converter | MT3608 (3.7V LiPo to 5VDC) | AliExpress Link |
Terminals | 3x 2P & 2x 3P | AliExpress Link |
Calib button | 12mm, no LED, (220V) | AliExpress Link |
C1 | Ceramic Capacitor 100nF | |
C2 | Electrolytic Capacitor 1µF | |
R10 & R4 1kOhm | TRIMPOT 1kOhm | AliExpress Link |
R5 & R7 2.2kOhm | Resistor 2.2kOhm | |
R8 10kOhm | Resistor 10kOhm | |
R9 220 Ohm | Resistor 220 Ohm | |
BCD Inflator Adapter | 3/8-24 UNF-2A | AliExpress Link |
Sensor Tube | 3D Part (holding the 2 sensors) | |
Housing | 3D Part (Analyser Box) | |
Back_Cover | 3D Part (Analyser Box, back cover) | |
Sensor Adapter | 3D Part (Tube to Sensor / Analyser) | |
Inflator to Tube | 3D Part (Inflator to Tube) | |
T-Piece | 3D Part (T-Piece to hold directly in front of tank) | |
T-Piece Sensor Adapter | 3D Part (Adapter from T-Piece to Sensor | |
Pneumatic Hose 8x5mm | AliExpress Link | |
Box Lid | 3D Part | |
Box bottom | 3D Part | |
Latch (2x) | 3D Part | |
Insert bottom | 3D Part | |
Insert Top | 3D Part | |
Housing:
Additional parts for gas sampling:
Parametric Box:
The circuit board was done in Fritzing
Idea & Arduino code is largely based on these two projects (adapted to my components and preferences):
https://github.com/captainigloo/Trimix-analyzer
https://www.godive-brandenburg.de/downloadse2467a8c
The author marked this model as their own original creation.