OPERATION IN HIGH WIND

TM 5-6675-250-10

2-18. OPERATION IN HIGH WIND

The SIAGL is designed to perform accurately in winds up to 20 mph (32 kmph). Wind disturbances

a.

can be detected by a difficulty in obtaining a steady BIAS null and extended observation times. In

winds in excess of 20 mph (32 kmph) it is recommended that the wind shelter be used to protect

the equipment and maintain an accuracy to performance.

To set up the wind shelter, erect lower panel assembly (1) by positioning edge of panel between

b.

metal brace and flap, and secure with snap fasteners (6). Place assembly over erected instrument

and position to prevent any contact with the instrument during operation. Pin the skirts (2) of the

lower panel assembly firmly to the ground with pins (3). Assemble the upper panel assembly (4);

stretch cover (5) over upper panel and secure with snap fasteners (6). When the instrument is

uncaged in the BIAS or GC mode, press upper panel assembly firmly onto lower panel assembly.

Remove the upper panel assembly to read azimuth. When operating in areas of sand or loamy

soils, place rock and sod over lower panel skirts and pins to provide maximum stability of the shel-

ter.

2-19. ELECTROMAGNETIC INTERFERENCE (EMI)

.

The SIAGL is susceptible to certain levels of electromagnetic radiation. In areas where frequencies of 30

K H z - 200 KHz are present, the READ Azimuth light will extinguish at levels from 0.10 volts/meter. At fre-

quencies from 30 MHz to 40 MHz the Gyro will cage at levels of 5.6 V/M to 7.5 V/M.

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