| Description: | An inexperienced AOS technician inadvertently closed off the flow to the dual-nephelometer
humidograph system during a Friday Preventative Maintenance. This resulted in liquid
water getting into the humidified nephelometer. Flow was restored to the system on Monday,
but the nephelometers were producing strange data. A number of tests were performed
over the next few days to remotely troubleshoot the situation, to no avail. Eventually, the
decision was made to pull both nephelometers and return them to Boulder for repair.
This DQR refers only to the reference nephelometer, which was out of service for 2 periods
due to 2 separate problems. This DQR is for the second period, from 000620 (1340 GMT) to
000703 (1833 GMT). Light absorption measurements are invalid whenever the reference
nephelometer is not operational, because those data are required for correction of the
absorption data. |