Time Correction Processing; Gps Event Function - Hioki PW9005 Instruction Manual

4.2 Time Correction Processing

The PQ3198 performs time correction when the PW9005 has acquired GPS satellites and
calculated its position.
Two types of time correction are used, depending on the PQ3198's operational status: con-
tinuous time correction and millisecond time correction.
Continuous time cor-
rection
Millisecond time cor-
rection
The precision of the PQ3198's internal clock is 0.3 s/day (at 23°C ±5°C). If
the PW9005 is unable to detect its position for a certain period of time
(about 1 hour), the difference between the PQ3198's internal clock and
GPS time may exceed 16 ms.
A GPS event is generated and time correction is halted during subsequent
recording if the difference between the PQ3198's internal clock and GPS
time exceeds 16 ms while the PQ3198 is recording, since such a large dif-
ference would compromise the measurement data's time consistency.
(Once recording is stopped and the PQ3198 returns to
continuous time correction is used.)

4.3 GPS Event Function

When the GPS status changes after recording has been started with the PQ3198 in the
time-corrected state (with a blue GPS mark), the next GPS event is generated.
1. GPS error (GPS IN)
Indicates that a GPS error has occurred.
(The instrument changed from the time-corrected state [blue GPS mark] to the error
state [GPS mark other than blue].)
2. GPS position detected (GPS OUT)
Indicates that the GPS error was cleared.
(The instrument changed from the error state [GPS mark other than blue] to the time-
corrected state [blue GPS mark].)
3. GPS time error (GPS Err)
Indicates that GPS time correction is not possible.
(The difference between the PQ3198's internal clock and the GPS time reached or
exceeded 16 ms.)
Chapter 4 PQ3198 GPS Positioning and Time Correction
Continuous time correction is performed while the PQ3198 is in
[SETTING]
mode. The PQ3198's time data is corrected with time
data acquired from GPS satellites once every second. As long as the
GPS mark is blue, the PQ3198 is synchronized with GPS time.
Millisecond time correction is performed whenever the PQ3198 is not in
[SETTING]
mode. As long as the difference between the PQ3198's
internal clock and the GPS time is less than 16 ms, time correction is per-
formed once every 30 seconds using millisecond units.
HIOKI PW9005A980-06
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[SETTING] mode,