Onset has a neat Bluetooth Hobo water level logger. The MX-2001, with the cap removed, hooks up to the MX-2001-TOP with a cable, and once installed, is
downloaded with the free Hobomobile smartphone app. The app does everything you’d normally need a data shuttle and cable for – starting, setup, configuration, downloading, and stopping the logger.
The top unit with the Bluetooth radio has to be out of the water, so of course the top of the stilling well holding the unit has to be 1.0 feet or higher up out of the water. If the stilling well is galvanized iron pipe, you’ll need to get within a few feet to download it. If you are using PVC you might get a connection at 100 feet.
Will two units close to each other interfere? Nope, the app finds both and lets the user choose which unit to work with. As with any water level logger installation, keep a logbook or spreadsheet with the Serial Numbers for each location so you aren’t confused later.
What about barometric pressure? The TOP unit records barometric pressure, so you don’t need a second unit for atmospheric pressure, nor do you have to know the elevation difference between two separated units. The unit subtracts atmospheric from absolute pressure, then gives you all 3 values when you download: absolute, atmospheric, water only. That makes data processing much easier.
In California, you should be able to get one of these shipped to you for $750. Compare that to the regular Hobos, which need one in the air, one in the water, and a data shuttle and cable. It would put you back almost $1,000 to get the separate pieces shipped to you. If you have two or more locations to log, then the old style is less expensive as far as parts go. Still, the Bluetooth version is likely more cost effective when you consider the minutes saved each time the Bluetooth unit is downloaded, compared to unlocking or unscrewing the cap, getting the water unit out, downloading it, and replacing the cap or lock.