Reports
Contents
| Title: | Eosense CO2 Probe Compare | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Date: | 2018-04-23 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Data File: | EosGP_Compare_20180423_A.csv EosGP_Compare_20180423_B.csv |
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| Refers to: | GP20150101,GP20160096,GP20140084,GP20160127,GP20140088,GP20150109,GP20150111,GP20160127 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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On April 23 and 30, 2018 an inter-comparison of Eosense CO2 probes left in the lab was performed. A follow up inter-comparison was done on 2018-09-01 and can be found here: Eosense CO2 Probe Compare. The probes were compared in two batches against a new ("master") probe. The probes were put into a plastic box and the CO2 level was raised to 2%-3% and allowed to dissipate back to near ambient levels. The data was recorded at 10sec intervals by a CR1000. The analog range of all the probes is their range plus 20% CO2 (ppm) = mV / 5000 * (1.2 * range) Temp (C) = mV / 5000 * 70 - 20
Figure 1. Time series for Batch A. All probes were maxed out with only sn GP20150101 not following the others.
Figure 2. Regressions for the Batch A probes against the Master sn GP20160127. The relationships seem robust but sn GP20150101 seems to have a slope offset of about 18%. Figure 3. Time series for Batch B. Two of the probes have a much higher range (8%) and one, sn GP20140088 is very noisy and offset.
Figure 4. Regressions for Batch B probes against the Master sn GP20160127. As expected sn GP20140088 looks bad but the other two seem okay. Both of these runs were done using my breath to raise the CO2 concentration in the plastic box. I tried to use a 1% CO2 cal gas but could only get the concentration in the box up to about 0.675% - maybe need a higher flow rate or seal the box better.  Conclusions:
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