9225 - Lil' Devil II Low-Cost Multi-Tank Monitor

9225 – Lil’ Devil II – low-cost tank monitor

Low-Cost, Indoor, Multi-Tank, Local-and-Remote Tank MonitorLevel Devil II front panel - Tank 05 shows 206 gallons
The 9225 Lil’ Devil II is the greatly-improved new version of our popular Lil’ Devil tank monitor (long a popular industry leader in low-cost tank monitoring).
The Lil’ Devil II measures and monitors many different non-volatile fluids in vented tanks, and is especially popular as a water or oil tank monitor.

With our original cellular communications remote-monitoring and alerting features, this new system adds a digital display on the unit, and serves more tanks, plus other improvements.

This low-cost solution has a powerhouse of features, including:

Remote tank-level information at your PC,9225 Lil' Devil II communications to screens
for up to 5 tanks, via cellular* telecommunications.

Live data on the digital display panel for local readings.

Readings automatically posted to a secure, password-protected, private web page or to the Level Devil app on your smartphone, for remote monitoring. (Includes current data, data history, and graphs)

Alert e-mails / text messages / automated voice messages sent to you automatically when a fluid level gets too low, or too high (levels preset to your specifications), 

NEW!* The Lil’ Devil II now uses 4G/LTE Cat M1 cellular communications — which covers the United States, and most of the cellular telecom world — extending its useful life well into the next decade!

Use with indoor, non-pressurized, vented bulk tanks, containing:

    • Motor Oil & other Lubricants
    • Water
    • Anti-freeze
    • Concrete Additives
    • Paper recycling pulp mix
    • & many other fluids.
  • Ideal for many fluids where instrument-clogging is a common problem.

(NOTE: Not intended for use where slight water-condensate contamination would be a problem. Some small amount of condensate may be induced by instrument, especially during high humidity).

Extra Benefits:

  • Installs quickly and easily
  • Low-cost option for monitoring up to 5 tanks
    (for more tanks, just add additional units)


The Lil’ Devil II tank monitor is designed to be installed quickly and easily — for use with non-pressurized bulk tanks containing motor oil, lubes, water, antifreeze and many other fluids.

Bubbler system includes pump and sensor above tank, and tube to bottom of tank.
Especially popular as a water or oil tank monitor, Lil’Devil II™ actually measures many different fluids in vented tanks.

Lil’ Devil II is a “bubbler” system:

When prompted, the monitoring unit pumps a tiny amount of air through a tube to the tank, and measures the pressure required to force air bubbles out through the open end of the tube, at the bottom of the tank.  The amount of air pressure needed to pump the bubbles varies with the weight (and volume) of the fluid.

The pressure information is used to automatically calculate the vertical height (depth) of the fluid in the tank.  Then, using the tank size and geometry information stored in the system’s database, Level Devil® software calculates the actual gallons remaining in the tank and provides a digital read of the level — either on the tank monitor local display, or in a secure, password-protected online web page (accessible from your computer, tablet or smartphone).


Fluids: Oil, Antifreeze, Paper pulp mix, Water, Wastewater & many other fluids.

Maximum monitoring capacity: 5 tanks

Tank type: Non-pressurized

Maximum fluid height: 16.7 feet (5 m.) WC

Accuracy: Better than 1% of span.

Maximum Distance from Tank: 150 feet

Output communications:  Cellular telecom to Internet, for:

    • Display on password-secured webpage
  • Back-end processing, such as:
      • e-mail notifications
      • high-level / low-level alerts
    • custom data transfers to your system

Displays: [Tank #] and [Quantity]*
*(Quantity by volume or height, or other customer specification)

Min.Tank Port size: ¼” O.D. plastic tubing

Power: 120 Volts AC, 20VA

Built-in status tester: AC Loss / Disconnect notification (optional, with battery backup)

Weight: 3 pounds (1.2 kg.)

Dimensions: 9″W x 6″H x 4″D

Mounting location: Indoors, out of weather / dry environment.

Call us for more information:  (800) 886-2511

Downloadable Specifications Sheet (PDF)

Press Release (PDF)

Why Level Devil?