Weather Station Annual Maintenance

LTER Weather Station Annual Maintenance

In addition to weekly maintenance, annual maintenance may be required for certain instruments. <a href = “http://lter.kbs.msu.edu/Data/table.jsp?Product=KBS002-003&limitBy=Location&containing=LTERWS&format=record”>KBS002-003 lists the instruments currently deployed at the weather station. Check the serial numbers in the field to verify that the list is correct. Determine how long the device has been deployed by looking up its serial number in <a href = “http://lter.kbs.msu.edu/Data/table.jsp?tools=show&Product=KBS002-004&limitBy=Instrument&format=record”>KBS002-004. Service or replace the instrument as appropriate, referring to the instrument manual on file with the LTER Information manager (summary provided below). Light, wind, and humidity sensors are typically rotated, i.e., swapped for freshly calibrated instruments of the same type, and sent to the manufacturer for recalibration. Any time an instrument is removed or placed, the event should be reported to the information manager and logged in the instrument tracking system (KBS002-004). All instruments should be monitored throughout the year, and replaced/serviced if suspect.

Most instruments can be serviced from the ground, or by climbing a short distance up the tower. To service wind instruments, a crew of four people can “drop” the tower. Attach a rope halfway up the tower and have one person handle the rope to control descent. Carefully remove the retaining bolts on the southwest leg, and lower bolts on the other two legs. Tower will pivot on remaing bolts. Slowly lower the tower toward the northeast, using remaining personnel. Support lowered tower on saw horses to prevent damage to wind instruments or instrument enclosure. Caution! Tower is heavy. Do not attempt this operation without sufficient help.

Instrument-specific comments

• Belfort weighing bucket precipitation gauge: manual specifies annual cleaning. Check calibration annually: 1.0 L of water added to the bucket should cause a pen displacement of 24.4 chart units (1.22 inches). Report the results.

• HMP45C Temperature and Relative Humidity Probe: rotate annually.

• LI200X Pyranometer: rotate every two years.

• LI190SB Quantum Sensor: (Manual does not specify recalibration interval.) rotate every two years.

• 107 Temperature Probe. No recalibration or replacement interval is recommended. Check recent data to see that HMP45C and 107 agree.

• 014A Wind Speed Sensor. rotate annually (send to Met-One).

• 024A Wind Direction Sensor. rotate annually (send to Met-One).