Aircraft Liquid-Level Sensors
Aviation and aerospace operate at the very edge of tolerance, where the media is often exotic and the margin for error is nearly zero. For over 75 years, Krueger Sentry Gauge has engineered high-grade instrumentation for organizations that research, design, manufacture, operate, and maintain aircraft and spacecraft — all built in Green Bay, Wisconsin from American-made components in compliance with the Buy American Act.
Most of our aircraft liquid-level sensors are made from stainless steel (316L), with chemically resistant plastics and other materials available for specialized media, and our in-house machine shop gives us the flexibility to engineer gauges for unusual requirements. Our aviation line includes:
- Custom-Engineered Sensors
- Liquid-Level Gauges
- Overfill Alert Gauges
- Leak Detection Gauges
Aviation Tank Gauge Applications
From fueling operations to ground-support and maintenance facilities, aviation stores and handles a range of fuels and specialized fluids that demand precise, reliable measurement. Our decades of experience help us engineer gauges for the exotic media used across these industries. Common applications include:
- Aviation fuel (Avgas & Jet A)
- Ground-support fueling
- Hydraulic fluid
- De-icing fluids
- Lubricants & oils
- Specialty & exotic media
Engineered for Exotic Media
Aerospace applications often involve fluids that quickly degrade standard equipment. With over 75 years of experience and an in-house machine shop, Krueger Sentry Gauge has the knowledge to engineer gauges capable of monitoring the specialized media used throughout aviation and aerospace. Media and applications we support include:
Aviation Fuel Gauges
Avgas and Jet A fueling operations depend on accurate, reliable level indication to keep aircraft moving safely and on schedule. Our gauges give ground crews a clear reading during fueling and storage.
Hydraulic Fluid Gauges
Aircraft and ground-support hydraulic systems require clean, precisely monitored fluid. We build gauges whose wetted materials protect the fluid and hold their accuracy over time.
De-Icing Fluid Gauges
De-icing operations need dependable level readings on bulk fluid storage, often in harsh outdoor conditions. Our durable gauges are built to keep reading accurately through the season.
Exotic & Specialty Media
When an application calls for an unusual fluid or a demanding material spec, our engineering and machining capabilities let us build a gauge to suit. Tell us the media and the requirement, and we’ll match the gauge to it.
Jet A Fuel Gauges
Jet A fueling operations depend on accurate, reliable indication to keep aircraft moving safely and on schedule. Our gauges give ground crews a clear reading during fueling and bulk storage.
Avgas Gauges
Avgas storage and fueling require dependable level indication under demanding conditions. Our stainless-steel gauges are built for accuracy and durability in these high-consequence operations.
Aviation Lubricant Gauges
Aircraft and ground-support lubricants need clean, precisely monitored storage. We build gauges whose wetted materials protect the fluid and hold their accuracy over time.
Ground-Support Fluid Gauges
From hydraulic fluid to de-icing agents, ground-support operations store a range of specialized fluids. Our gauges are engineered to match the media and keep reading accurately in the field.
Built for an Industry That Can’t Afford a Guess
Aviation and aerospace demand precision at every level, from the hangar floor to the launch pad. At Krueger Sentry Gauge, we’re proud that our American-made instrumentation — engineered for even the most exotic media — helps this industry operate with the accuracy and reliability it requires.
Frequently Asked Questions
Got questions? Get answers instantly by browsing our FAQs below, chatting with our AI assistant, or reaching our to our team directly.
What do we use as a part number?
At Krueger Sentry, we don’t use classic part numbers. Everything is description-based. Refer to your product’s Spec Page (materials options) and the Order Info (tank measurements) page for more information. Example Part Number: – H-2-48 + 12 w/glass (H signifies the type of gauge, 2 is the size opening, 48 is the tank depth, 12 is the extension, and everything after that is the options you want to be included.
Which liquid level monitor is the right choice for me?
When choosing a liquid level gauge, different factors can change which sight gauge is best for you. The basic factors that motivate people to buy each type of gauge are as follows.
- Economical sight gauge- At-A-Glance Direct Reading
- Versatile sight gauge- Therma Gauge
- Small tank monitor, under 12 inches – The L Gauge
- Standard Barrel Level Gauges – Barrel Gauge
- Up to 12 feet of mechanical remote capability – Remote Reading Gauge
- Durability – GFK Gauge – you can achieve this durability by ordering a therma gauge with a gauge guard as well.
How do I find or locate a Krueger Sentry Gauge distributor?
Search our Preferred Distributor Page. Don’t see a distributor you want to use? Call me. Lee Geurts: 920-434-8860 ext 204
Which sight gauge do you recommend most often to your customers?
I try to sell the Therma gauge to most people. It is nearly as inexpensive as the At A Glance Gauge, but you have more control over your swing arm. Plus, this level gauge can be fitted with the most options.
What is the difference between the Type D At a Glance Level Gauge and the Type H Therma Level Gauge?
The Swing arm on the Type D Gauge is fixed. When you thread in the gauge, the swing arm spins inside the tank and will end up facing in a random direction. The swing arm on the Type H Gauge can be aimed in the exact direction you want it to swing, and when you thread the gauge in it does not spin inside the tank.
How long is the swing arm on a level gauge?
The arm is always half the depth of your tank.
How do I order a custom-size level gauge?
In order to get an accurate gauge for your tank, we take two measurements into consideration. First, we measure, in inches from top to bottom, what the distance is from empty to full, known as tank depth. Second, the distance from the full mark to the gauge fitting on top is also known as an extension length. Sometimes this measurement comes out to zero.
How do I prevent my tank gauge from getting damaged by the sun and weather?
Ordering upgraded options such as Solid Glass Tops and Gauge Guards will make your Krueger Gauge nearly impervious to weather, sun, and damage.
Can I repair just the top of my Tank Gauge, or do I need to replace the whole thing?
If your gauge still seems functional, you can replace just the top components by ordering the corresponding repair kit. Repair Kits are available for all gauge types and come in a variety of material options for added durability, which can be found in the Tank Gauge Accessories.
What is the recommended maintenance/testing for Krueger Leak Gauges?
Krueger Sentry provides a Leak Gauge Functionality / Calibration Testing Report with inspection procedures for inspectors/technicians. Please contact us with any questions.
