4 ms·

Any thoughts on the Sensirion SCD41? It is almost half the price. https://sensirion.com/products/catalog/SCD41/ https://sensirion.com/products/catalog/SCD41/

Any thoughts on the Sensirion SCD41? It is almost half the price. https://sensirion.com/products/catalog/SCD41/ https://sensirion.com/products/catalog/SCD41/ https://www.digikey.com/en/products/detail/sensirion-ag/SCD41-D-R2/13684005 https://www.digikey.com/en/products/detail/sensirion-ag/SCD4...

Youden 4y ago
The SCD41 is a very different sensor. The Senseair Sunrise requires through-hole assembly, uses a low-power version of NDIR and is relatively bulky. The SCD41 requires surface mount assembly, uses a higher-power proprietary technology based on MEMS and is very compact for a CO2 sensor. Personally I've been very happy with Sensirion's sensors and I've played with the SCD41 quite a bit. The trouble with it for hobbyists is the assembly. It has what seems to me to be pretty picky requirements for soldering. I've attempted to do it myself but I keep managing to pop off the metal covering. Haven't tried the Senseair Sunrise but such low power requirements are very very appealing because they mean the sensor can be battery-powered. The SCD41 isn't bad but powering it for a year means a lot more batteries. With a 1 min sampling period, the SCD41 uses 1.5mA while the Sunrise uses 21µA.
- joshvm 4y ago
  I've used these before from Amphenol/Telaire: https://www.amphenol-sensors.com/en/telaire/co2/525-co2-sensor-modules/3215-t6700 https://www.amphenol-sensors.com/en/telaire/co2/525-co2-sens... I think they're around 60 bucks (e.g. the T6793) so they aren't the cheapest around, but they're good quality. They have a normal header you can solder a few wires into. Probably the best approach for the Sensirion sensor is to oversize the pads a bit and use paste to re-flow underneath.
  - Youden 4y ago
    I have quite a few of the older T6613/T6615 sensors that I got when Newark was selling them for like $10 a piece. The way I soldered the SCD41 is with a pre-made PCB footprint, some solder paste and a mini PCB heater. I think the problem was too high heat. I need to try it again with low-temperature solder paste. But for my application the Senseair Sunrise looks a lot better.

Youden 4y ago

The SCD41 is a very different sensor. The Senseair Sunrise requires through-hole assembly, uses a low-power version of NDIR and is relatively bulky. The SCD41 requires surface mount assembly, uses a higher-power proprietary technology based on MEMS and is very compact for a CO2 sensor. Personally I've been very happy with Sensirion's sensors and I've played with the SCD41 quite a bit. The trouble with it for hobbyists is the assembly. It has what seems to me to be pretty picky requirements for soldering. I've attempted to do it myself but I keep managing to pop off the metal covering. Haven't tried the Senseair Sunrise but such low power requirements are very very appealing because they mean the sensor can be battery-powered. The SCD41 isn't bad but powering it for a year means a lot more batteries. With a 1 min sampling period, the SCD41 uses 1.5mA while the Sunrise uses 21µA.

joshvm 4y ago
I've used these before from Amphenol/Telaire: https://www.amphenol-sensors.com/en/telaire/co2/525-co2-sensor-modules/3215-t6700 https://www.amphenol-sensors.com/en/telaire/co2/525-co2-sens... I think they're around 60 bucks (e.g. the T6793) so they aren't the cheapest around, but they're good quality. They have a normal header you can solder a few wires into. Probably the best approach for the Sensirion sensor is to oversize the pads a bit and use paste to re-flow underneath.
- Youden 4y ago
  I have quite a few of the older T6613/T6615 sensors that I got when Newark was selling them for like $10 a piece. The way I soldered the SCD41 is with a pre-made PCB footprint, some solder paste and a mini PCB heater. I think the problem was too high heat. I need to try it again with low-temperature solder paste. But for my application the Senseair Sunrise looks a lot better.