NOTE: The ID-2447/U indicator (fig. 2-25) is a recent addition to the UMQ-5 system. The indicator is found in weather offices and in Marine Corps radar support spaces, with the primary readout in the Air Traffic Control Center. The indicator provides average, minimum,  and  maximum  wind  speeds.  For  more information  on  the  ID-2447/U  indicator,  see  the operating and maintenance instructions. Typically, the wind speed and direction indicators and  wind  speed  recorders  are  installed  inside  the weather office, while the transmitter is installed on an MT-535/UMQ-5 support mast near the runway or on a rooftop. Operation and Maintenance Operation and maintenance instructions for the different   components   of   the   AN/UMQ-5   wind- measuring set are detailed in several manuals. Consult the manual for the model installed in your office. NA 50-30FR-525, the Handbook of Operation and Maintenance Instructions for Wind Measuring Sets AN/UMQ-5C and AN/UMQ-5D,  covers the newer models, including instructions for the later model RD- 108(B) chart recorders. NA 50-30FR-501 covers the AN/UMQ-5(A)  system,  and  NA  50-30FR-512  covers the AN/UMQ-5(B) system. Instructions for the older model  recorders  (RD-108/UMQ-5  and  RD- 108(A)/UMQ-5) are covered in NA 50-30FR-505, the Handbookof Operation and Service Instructionsfor the Wind Direction and Speed Recorder RD-108/UMQ-5. TRANSMITTERS AND INDICATORS.—Very little operator attention is required for this equipment. The operator’s handbook recommends a daily visual check of the transmitters and indicators, and a weekly Figure 2-25.—ID-2447/U wind speed and direction indicator. visual inspection of the transmitter. Jerky movement of the impeller or failure of the wind vane to follow light winds indicates an overhaul is due. Finally, a quarterly friction check is recommended. The transmitter is removed and bench tested with penny and half-dollar weights to check for excessive friction. WIND  RECORDER.—The  analog  wind  recorder requires  somewhat  more  attention.  The  recorder  pens mark a continuous output of wind direction and wind speed on a continuous, two-column chart (fig. 2-26). The wind direction column, on the left side of the chart, has vertical lines drawn for every 10 degrees; these are labeled every 90 degrees, along with the cardinal compass points. The chart covers 540 degrees to allow for shifting winds. The wind speed column, on the right side, has vertical lines drawn every 2 knots; these are labeled every 20 knots, from 0 to 120 knots. Curving lines across the chart mark the time every 10 minutes and are labeled for every hour, in the center divider strip. Many recorders have been modified to use preinked pen cartridges, which are simply replaced as a unit when the ink runs dry.   Some units still use the older model pens and inkwells. The older pens must be checked frequently;  a  line  that  skips  on  the  chart  usually indicates a dirty pen. A  standard,  100-foot,  wind  speed  and  direction recorder chart, when operated at the standard speed of 3 inches per hour, will run for 15 to 16 days before it requires changing. Instructions on how to replace the chart in the recorder are contained in the handbook on operation and maintenance. Recorder Charts The analog recorder charts should be carefully preserved and treated as a permanent official record. Each recorder chart roll should be identified at the start and end of the roll, with the station name and the date and time the recording began and ended. The chart is adjusted so the times marked on the chart correspond to UTC. The chart should be changed at 0000 UTC on the first day of each month and at intermediate times to prevent the loss of data.   See  NAVMETOCCOMINST 3141.2 for more information. TIME CHECKS.—Time checks are made on the recorder chart by drawing a short line on the recorder chart where the pen is marking data, and entering the date and time to the nearest minute. At the minimum, time checks are required as follows: At the beginning and end of each chart roll 2-19