Reports
Contents
| Title: | Eosense CO2 Probe Compare | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Date: | 2018-09-07 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Data File: | EosGP_Compare_20180907.csv | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Refers to: | GP20150101,GP20140084,GP20150109,GP20160127,GP20140026 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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This is a follow up to the April inter-comparison. In this inter-comparison there is one new probe sn GP20140026 and three others were retested. Again, the probes were put into a plastic box and the CO2 level was raised to 2%-3% with my breath and allowed to dissipate back to near ambient levels. However, this time I flowed some zero air into the box at the end. The data was recorded as single ended millivolts 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. All probes followed roughly the same path.
Figure 2. Linear regression. All relationships seem tight although slightly offset. There seems to be a slight change in slope below 500ppm but it is small and in use these probes mostly will not see low values. The probes that were retested match their previous comparisons relatively well especially considering the change of pulling them down to zero with the zero air. Conclusions:
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