Equipment and Calibration History

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View history entry 5717 for Licor LI-7500A sn: 75H-2514

Date: 2022-03-09
From: Lab - none
To: Lab - none
Title: Maintenance
Notes: We ran zero air through this sensor today. The CO2 zero was fine at 1.21 ppm. The H2O zero was large at -26.8 mmol/m3 (previous H2O zero from last week had a +30.2 mmol/m3 offsets). In addition, the H2O zero changed depending on the orientation of the sensor. When laying on the bench, it was around -20 mmol/m3. When the top of the sensor was propped up slightly, the offset jumped to around -10 mmol/m3 and stayed steady. When we laid the sensor down again, the offset dropped to -20 mmol/m3 again. Joe didn't hear anything change inside the sensor when we were moving it around. We decided to change the internal chemicals. The old chemicals seemed ok. We flushed out the headspace with zero air before sealing it up again. I'll let it run on the bench for a few days before calibrating it again.
Entered by: Daphne Szutu