OceanServer Technology OS5000 Series Faq

OS5000 Family of Compasses FAQ Document Rev. 1.0
Please also reference the OS5000 family user guide on our download page
Q. What is the standard OS5000 string and can I change it to a different
format ?
A. OceanServer's standard digital compasses output heading, pitch, roll and
temperature. You can change the displayed parameters such as adding the raw 3 axis
accelerometer and 3 axis magnetic sensor data. There are also several different
compass formats to choose from (Standard Compass String:
$C320.5P0.2R-
18.3T19.0*3C)
Q. Is there any way to check the heading accuracy?
A. A precision compass will measure the field very accurately. If you're near ferrous
metals, DC currents or magnetic devices (motors), etc, the earth's field will be distorted.
This can cause a large error in heading. You can verify the field distortion by using a
second compass and comparing results to the OS5000 (for example: a low cost
magnetic needle compass is a quick and simple way to see how your equipment shifts
the position of true north).
Q. Should I be concerned about other components in my system in the near
vicinity of the compass?
A. Yes, many components contain ferrous materials. Nickel will commonly be found in
integrated circuit designs. Other components such as batteries, speakers, power
transistors with iron, microphones can all present issues. The compass should be kept a
safe distance from these items. The fields fall off as an inverse square of the distance so
doubling the distance reduces the field strength by ¼.
Q. Can the compass be calibrated indoors in a metal building?
A. For the highest accuracy you should calibrate the compass in its final mounting
outdoors away from cars or metal structures. The compass will learn a hard iron offset
of the steal building if calibrated indoors and will have errors in a clean environment.
Q. What is the impact of metal structures in the field?
A. The compass calibration routine will make corrections for the device in which the
compass is mounted. The earth's magnetic field will be distorted by magnetic anomalies
that may existed in the outside world such as a steel bridge, building etc. The compass
heading will be impacted by the degree of the distortion while passing by such