Independent checking of On-board Barometers
Atmospheric Environment and Ocean Division, Atmosphere and Ocean Department, Japan Meteorological Agency
This website provides information on a simple method for independent checking of on-board barometers.
For barometer reading:
- Anchor in a Japanese port.
- Avoid reading in strong wind, as this may affect results.
- Open windows/doors for equalization with outboard air pressure.
- Take readings EXACTLY ON THE HOUR.
Obtaining data for barometer calibration
1. Download the Excel check worksheet from the link below.
2. Enter the relevant barometer values in the worksheet cells.
2-1. Barometer height above sea level and barometer reading
- Current barometer height above sea level (unit: meters)
- Barometer heights above sea level both in ballast and at full load (unit: meters)
- Barometer reading (unit: hPa as read exactly on the hour)
Note: The height at full load cannot be greater than that in ballast.
Inputting barometer data
2-2. Meteorological data from the nearest weather station
- Select the port of call from the drop-down menu below and click GO! to show meteorological data from the nearest weather station to it. Ports and stations can also be selected from the map.
- Use the table to determine sea level pressure and temperature at the time the barometer was read (shown in JST).
- In this example, at the barometer reading time of 09 JST, the temperature was 12.0°C (red) and the sea level pressure was 1007.1 hPa (orange).
- Enter the relevant values in the worksheet cells.
Inputting meteorological data
3. The green and blue cells show barometer check results.
- Keep the results until the next barometer check.
- Add the total of the blue fields to the barometer reading to determine sea level pressure.
Weather Station Map
Disclaimer
- The Japan Meteorological Agency (JMA) accepts no responsibility for any damage or loss sustained as a result of this website's use.