9.1.3 Barologger Installation

The Barologger is a Levelogger with a small range of 1.5 m (4.92 ft) adequate to monitor the fluctuations that occur in barometric pressure. The Barologger’s readings are used to barometrically compensate Levelogger readings. Typically, Barologger readings range from 1 – 3.3 ft (30 – 100 cm) when the Barologger is programmed with its operating altitude. Failure to input the correct altitude with result in incorrect readings and may cause the pressure transducer to go out of range. It is strongly recommended that the altitude input be accurate to 10 m. When the Barologger is programmed at its operating altitude, its readings can be used to directly compensate for barometric pressure, the readings of any Levelogger programmed at the Levelogger’s operating altitude. As a rule or thumb, a Barologger can be used to compensate all the Leveloggers in a 20 mile (30 km) radius.

To monitor barometric pressure correctly, the Barologger should never be submerged. In well installations, it is recommended that the Barologger be suspended in one of the monitored wells above the high water point (Figure 9-8). For best reading accuracy, the Barologger should be installed in a similar thermal environment to that of the Levelogger. In groundwater wells, the Barologger should be suspended beyond the frost line and deep enough to avoid large temperature fluctuations. In surface water applications, the Barologger is best deployed in a dry well – a well embedded in the bottom of the water body, but sealed at the base from water entry and vented to the atmosphere. If a dry well cannot be installed, the Barologger can be installed on a float in the stilling well. Further information on the Barologger and barometric pressure can be found in Section 10.