YSI 556 MPS - Manual (Page 94)

Section 10 System Setup
YSI 556 MPS YSI Incorporated Page 88
10.11 Calibrate Barometer
The optional barometer has been factory calibrated to provide accurate
readings. However, some sensor drift may occur over time, requiring
occasional calibration by the user, as follows:
1. Determine your local barometric pressure from an
independent laboratory barometer or from your local weather
service.
2. If the barometric pressure (BP) reading is from your local
weather station, reverse the equation that corrects it to sea
level.
NOTE: For this equation to be accurate, the barometric
pressure units must be in mmHg.
True BP = (Corrected BP) – [2.5 * (Local Altitude/100)]
3. Go to the system setup screen as described in Section 10.1
Accessing the System Setup Screen.
4. Use the arrow keys to highlight the Calibrate barometer
selection on the system setup screen. See Figure 10.2 System
Setup Screen.
5. Press the Enter key. The Calibrate Barometer screen is
displayed.
Figure 10.6 Barometer Calibration Screen