9.6.4 Operational Checks and Preventive Maintenance

Like all monitoring equipment, upper-air instruments require various operational checks and routine preventive maintenance. The instrument maintenance manuals should be consulted to determine which checks to perform and their recommended frequency. The quality and quantity of data obtained will be directly proportional to the care taken in ensuring that the system is routinely and adequately maintained. The site technicians who will perform preventive and emergency maintenance should be identified. The site technicians serve a crucial role in producing high quality data and thus should receive sufficient training and instruction on how to maintain the equipment. Some general issues related to operational checks and preventivemaintenance should be addressed in the QAPP, including:

• Identification of the components to be checked and replaced



• Development of procedures and checklists to conduct preventive maintenance



• Establishment of a schedule for checks and preventive maintenance.



• Identification of persons (and alternates) who will perform the checks and maintenance



• Development of procedures for maintaining spare components that need frequent replacement 

Listed below are some key items to be included in the operational checklists for each of the different types of instrumentation. The list is by no means complete, but should serve as astarting point for developing a more thorough set of instrumentation checks.

• Safety equipment (first aid kit, fire extinguisher) should be inventoried and checked.



• After severe or inclement weather, the site should be visited and the shelter and equipment should be inspected.



• Computers should be routinely monitored to assure adequate disk space is available, and diagnosed to ensure integrity of the disk.



• A visual inspection of the site, shelter, instrument and its components should be made.



• Data should be backed up on a routine basis.



• If the remote sensors are operated during the winter, procedures for snow and ice removal should be developed and implemented, as needed.



• The clock time of the instruments should be monitored, and a schedule for updating the clocks established based on the timekeeping ability of the instrument.



• The antenna level and orientation of sodar, radar, RASS, and radio theodolite radiosonde systems should be verified periodically.



• The inside of the antennas/enclosures of the sodar, radar and RASS systems should be inspected and any leaves, dust, animals, insects, snow, ice, or other materials removed. Since the antennas are open to precipitation, drain holes are provided to allow water to pass through the bottom of the antennas. These holes should be periodically inspected and cleaned.



• Cables and guy wires securing the equipment should be checked to ensure that they are tight and in good condition.



• Antenna cables and connections should be inspected for signs of damage due to normal wear, moisture, or animal activities.



• For sodar systems, the site technician(s) should listen to assure that the system is transmitting on all axes and in the correct firing sequence. For three-axis systems, this is accomplished by listening to each antenna. For phased-array systems, this can be accomplished by standing away from the antenna in the direction of each beam and listening for relatively stronger pulses.



• The integrity of any acoustic enclosures and acoustic-absorbing materials should be inspected. Weathering of these items will degrade the acoustic sealing properties of the enclosure and reduce the performance.



• For a radar profiler with RASS, acoustic levels from the sound sources should be measured using a sound meter (ear protection is required) and readings should be compared with manufacturer's guidelines.

All operational checks and preventive maintenance activities should be recorded in logs and/or on appropriate checklists, (electronic and/or paper) which will become part of the documentation that describes and defends the overall quality of the data produced.

9. UPPER-AIR MONITORING 
9.1 Fundamentals  
      9.1.1 Upper-Air Meteorological Variables  
     9.1.2 Radiosonde Sounding System  
     9.1.3 Doppler Sodar 
     9.1.4 Radar Wind Profiler 
     9.1.5 RASS  
 9.2 Performance Characteristics  
     9.2.1 Definition of Performance Specifications  
     9.2.2 Performance Characteristics of Radiosonde Sounding Systems 
     9.2.3 Performance Characteristics of Remote Sensing Systems  
 9.3 Monitoring Objectives and Goals  
     9.3.1 Data Quality Objectives  
 9.4 Siting and Exposure
 9.5 Installation and Acceptance Testing 
 9.6 Quality Assurance and Quality Control 
     9.6.1 Calibration Methods  
     9.6.2 System and Performance Audits  
     9.6.3 Standard Operating Procedures 
     9.6.4 Operational Checks and Preventive Maintenance  
     9.6.5 Corrective Action and Reporting  
     9.6.6 Common Problems Encountered in Upper-Air Data Collection 
 9.7 Data Processing and Management (DP&M) 
      9.7.1 Overview of Data Products  
     9.7.2 Steps in DP&M 
     9.7.3 Data Archiving  
 9.8 Recommendations for Upper-Air Data Collection