The THD shall be tested for accuracy with the sensing part connected. If the sensing part is so designed that it is included in the transmitting part, the equipment shall be tested all parts.

　

　

　

Testing under ambient temperature all tests shall be carried out under ambient conditions, which are defined as at temperatures between + 10℃ and + 35℃ and relative humidity between 20% and 70%, with a Horizontal Dilution Of Position (HDOP). <4, PDOP >6 and a minimum of 5 satellites in view. and a HDOP<4. And if there is no other definition in the described test, the minimum of satellite in view shall be 5.

　

　

The sensing part shall be mounted on a table according to the manufacturer's instructions in an area providing clear line of sight to the satellites from zenith through to the angle + 5°above horizontal, with stationary, normally level aligned 000 ± 1°. The heading of the table shall be known to an accuracy of better than 0,1°.

　

Maximum cable lengths as specified by the manufacturer shall be used during testing.

　

All static tests shall utilize actual GNSS signals.

　

　

Mount the THD according to the manufacturer's instructions on the scorsby table in an area providing clear line of sight from zenith to the angle + 5°above the horizontal.

　

The dynamic test shall be utilize actual GNSS signals.

　

　

　

Mount the THD on the static test site to a known direction.

　

Record the time specified in 3.8 and it shall conform to the requirement specified in 4.6.

　

　

The THD shall be settled on the static test site specified in 6.2.2 and the table aligned to an optional direction. The THD shall be settled on the static test site specified in 6.2.2 aligned the table to an optional direction. Heading measurements shall be taken over a period of not less than 20 minutes.

　

The distribution of the [1 000] measurements shall not be in error with the known direction by 1°95%, having discarded measurements taken in conditions of HDOP>4 and PDOP>6.

This test shall be repeated changing the table direction in steps of 45°± 5°.

　

　

Choosing one of the following methods, dynamic test shall be carried out.

　

The test shall be carried out for a period of at least [ 5 ] min.

　

a) Scorsby test

　

The THD shall be mounted on the dynamic test site specified in 6.2.3 with the table stationary, normally level and its roll axis aligned North-South within ±1°.

　

The THD shall be aligned to within ± 1°of the table roll axis. The following nominal simple harmonic motions shall be applied simultaneously to the three axes of the table for [ 5 ] min.

　

― roll axis : Peak amplitude 20°± 2°,period 6 s ± 1 s

　

― pitch axis: Peak amplitude 10°± 2°, period 10 s ± 1s

　

― yaw axis : Peak amplitude 5°± 1°, period 15 s ± 1 s

　

During the test, output from the THD shall be recorded. The difference between output and reference direction of the scorsby table shall be within ± 1,5°95%.

　

b) Vehicle test

　

The THD shall be mounted on the dynamic platform (vehicle or ship) that has the reference heading sensor whose dynamic accuracy is better than [ 0,2 1 ]°. The platform shall run satisfying the conditions below.

　

　

During the test output both from the THD and the reference sensor shall be recorded. The difference between two shall be within ±1,5°.

　

　

The THD on the static test site shall be turned at a rate not greater than 10°/s, to read data both of THD output and angle of the table at least 5°interval during this test.

　

The maximum follow-up error shall conform to the requirements specified in 5.4.

　

The THD on the static test site shall be turned at a rate not greater than 20°/s, to read data both of THD output and angle of the table at least 5°interval during this test.

　

The maximum follow-up error shall conform to the requirements specified in 5.4.

　

　

During static operation of the THD as required in 6.4, the sensing part shall be completely masked for a period of [60] s. At the end of this period, the output shall be recorded without delay.

　

The difference between the output at start and end of the test shall conform to the requirement in 4.5.

　

　

Unless otherwise stated in this standard, all the tests shall be carried out according to the requirement of IEC 60945.

　

The manufacturer shall determine which components of the THD system will be protected or exposed, as defined in IEC 60945.

　

　

Place the transmitting part in a test chamber and connect it via a signal line from the sensing part which is to be mounted at the static site.

　

Place the transmitting part in a test chamber and connect signal line from the sensing part which to be mounted at the static site.

　

During this test, according to the requirement of IEC 60945, the back up test specified in 6.7 in this standard shall be carried out at the output of the transmitting part.

　

　

Place the transmitting part on a vibration table and connect signal line from the sensing part which to be mounted at the static site.

　

During this test, according to the requirement of IEC 60945, the back up test specified in 6.7 in this standard shall be carried out at the output of the transmitting part.

　

　

The device, with regard to electromagnetic interference and immunity, shall in addition to IMO resolution A.694 (17), comply with IMO resolution A.813 (19).

　

Each unit of the equipment shall be marked with, the minimum safe distance at which it may be mounted from a standard and a steering magnetic compass. The safe distance shall be measured in accordance with ISO 694 and IEC 60945.

　

　

― the identification of the manufacturer;

　

― the equipment type number or identification of the model which was type tested;

　

― the serial number of the unit;

　

― the year of manufacture(not necessary if the year of manufacture can be read by the serial number);

　

The presence of the markings on the unit of the THDs specified as above shall be checked by visual inspection.