Acu-Gage
From Snake River Electronics ~ “Acu-Gage” Monitor Systems Calibration Note:You can calibrate the empty or full points in any order you wish. The reason that we specify calibrating the empty point first is that these units are typically installed at a factory on an empty tank so it makes sense in the OEM setting to do the empty calibration first.You can also "tune" the calibration by re-calibrating the full or empty points at any time that you wish. Sometimes the factory empty setting is not a realistic point due to the way that the plumbing works in most boats--the tank cannot be completely emptied out in normal operation--so resetting the empty point to a "pumped out" empty is probably a good idea.Regarding the 2 hour update, the display, audible alarm, and warning light, are all updated at the same time the panel reads all the sensors, so if you hear the alarm chirp then the data on the display current. When the display board reads all sensors it also returns to display the tank attached to channel 1 (i.e.: every 2 hours the display board returns to the tank displayed when the unit is first turned on). The red light and chirp alarm do not necessarily indicate that the displayed tank is out-of-bounds, these alarms indicate that one or more tanks are either too high or too low and you need to scroll through to find which ones (there may be more than one) are in need of attention. The display shows tank status in the upper-right-hand corner. If the tank is fine then OK is displayed. If a waste tank is getting too high then HI is displayed; if a fresh or fuel tank is getting too low then LO is displayed. If any tanks are showing either HI or LO then the red warning light is lit and every 2 hours the warning chirp will sound.Note that whenever you scroll up or down to a new tank, it is read and the new reading is displayed, so when you manually scroll through all tanks all readings are current (the red warning light might light up as you scroll because it is also updated with the new readings as you scroll through).Downloadable Tech’ Documents: http://www.snake-river.org/Literature.aspTech Support information: http://www.snake-river.org/TechSupport.asp