HMR3000

www.honeywell.com

5

APPLICATIONS PRECAUTIONS

Several precautions should be observed when using magnetic compasses in general:



The presence of ferrous materials, such as nickel, iron, steel, and cobalt near the magnetometer will create

disturbances in the earth’s magnetic field that will distort the X, Y, and Z field measurements.



Perming effects on the HMR3000 circuit board need to be taken into account. If the HMR3000 is exposed to fields

greater than 10 gauss, then it is recommended that the enclosure/circuit boards be degaussed for highest

sensitivity and resolution. A possible result of perming is a high zero-field output indication that exceeds

specification limits. Degaussing wands are readily available from local electronics tool suppliers and are

inexpensive. Severe field offset values could result if not degaussed.

NON-FERROUS MATERIALS

Materials that do not affect surrounding magnetic fields are: copper, brass, gold, aluminum, some stainless steels, silver,

tin, silicon, and most non-metals.

HANDLING PRECAUTIONS

The HMR3000 Digital Compass Module measures fields within 1 gauss in magnitude. Computer floppy disks (diskettes)

store data with field strengths of approximately 10 gauss. This means that the HMR3000 is many times more sensitive than

common floppy disks. Please treat the compass with at least the same caution as your diskettes by avoiding motors, CRT

video monitors, and magnets. Even though the loss of performance is recoverable, these magnetic sources will interfere

with measurements.

The fluidic tilt sensor works best when kept near level, and in calm to moderate vibration conditions. If turned upside down

or violently jarred, not all the fluid will immediately return to the bottom of the tilt sensor’s glass ampoule. Accurate tilt and

tilt compensated headings may be unavailable for a minute or two to allow for the fluid to transit to the bottom of the ampoule.

PCB DIMENSIONS AND PINOUT