Field talk for a staff-to-gauge comparison: an observer reads the tide staff repeatedly over a few minutes while the gauge logs, then the averages are compared. A consistent difference shows a datum offset, while a changing one shows sensor drift or a fouled well. Regular staff shots, especially at installation and removal, are what allow a short-term gauge to be tied to datum with confidence.
Staff shot this morning shows the pressure gauge reading 3 centimetres high, that's new since Tuesday.
Read the staff in calm water and average several readings; a single glance in chop can be off by more than the error being chased.
Also heard as
- staff reading
- staff-gauge comparison
- staff-to-gauge
Related terms
Tide staff
A graduated board fixed vertically in the water and read by eye to check a gauge against datum.
Pressure gauge
A submerged sensor that measures the weight of water above it, converted to water level with density and air pressure.
Stilling well
An upright tube fed through a narrow bottom intake, filtering out waves so the gauge inside sees only the slow tide.
Leveling
Precise measurement of height differences between bench marks and the gauge or staff using a level and rods.