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000036 Standard Model
000038 Intrinsically Safe Model

The UL101 Leak Detector quickly locates the ultrasound waves produced by compressed gas and vacuum leaks. Simply aim the leak detector in the direction of the piping and adjust the sensitivity to pinpoint the location of any leak with turbulent flow. The UL101 has the best signal-to-noise ratio and highest sensitivity in the market. Leaks sound like rushing air in the operator's head set, and the gain can be minimized to eliminate all or most ultrasonic "white noise" for an operator-friendly user experience. 

CTRL UL101 Leak Detector Ultrasound Listening Device (ULD)

Benefits of UL101 Acoustic Ultrasound Listening Devices


Simply adjust the sensitivity on the UL101 Leak Detector's handheld receiver to pinpoint the leak; scan areas from up to 300 feet away with the PowerBeam 300 parabolic accessory. 


Ultrasound travels in linear paths and doesn't tend to travel around corners or reflect. Using CTRL’s acoustic ultrasound listening products, leaks are not easily masked. 

No calibration needed

Acoustic ultrasound is used for indication and location, not leak measurement. Our leak detectors are ruggedized for use in the most caustic of environments, including power plants


Our UL101 Leak Detectors can find leaks faster and more accurately. Your systems can now run at normal and even improved vacuum levels to improve power turbine efficiency. 


The cost of a high end ultrasound detector is 3 to 5 times less than the cost of a helium leak detection system. CTRL’s UL101 products are priced competitively compared to industry leaders, require less training, and are faster to use. 


Leak Detection (Pressure & Vacuum)

Airborne ultrasound detection can be used to easily locate leaks within a noisy environment.

Electrical Inspection

Airborne ultrasound can be used to detect various electrical faults; including corona discharge, tracking, and arcing.

Valves & Steam Traps

Effective use of the UL101 for ultrasound detection on valves can reduce and even eliminate unnecessary overhaul costs, resources, and time. 

How the CTRL UL101 Leak Detector Works

Using ultrasound detectors for leak detection is a growing industry standard. Acoustic ultrasound leak detection is recommended by many, such as the U.S. Department of Energy, as the best method for detecting the location of leaks in order to minimize energy waste and improve plant efficiency.

The CTRL UL101 Leak Detector converts the ultrasound (40 kHz +/- 1 kHz) down into the audible range and outputs to a headset. All other frequencies are filtered, so that even the smallest air/gas, vacuum, or refrigerant leak can be detected and pinpointed in a noisy plant environment.

How UL101 Detects & Converts Ultrasound Into Human Audible Range of Hearing

Detect & Convert Ultrasound Into Human Audible Range of Hearing

Key Features

  • Fixed Frequency

  • High Sensitivity to all turbulent flow air, gas, or vacuum leaks

  • Easily adjustable sensitivity and gain

  • Lightweight, one-handed operation

  • Converts ultrasound to easily recognizable audible sounds

  • Standard 9-Volt Battery means no waiting to recharge

Intrinsically Safe

ANSI /UL 91 3-88, for DIVISION 1, CLASS I, Groups A, B, C and D, CLASS II, Groups E, F, G and CLASS III

It also complies with DIVISION 2, CLASS I, Groups A, B, C and D, CLASS II , Groups F, G, and CLASS III

Technical Specifications

UL101 Leak Detector Technical Specifications

Receiver / Transmitter Dimensions
8.75” x 1.26” x 1.26” (222 x 32 x 32 mm)

4.125" x 1.26" x 1.26" (105 x 32 x 32 mm)                            

Kit Shipping Dimensions    

17" x 8" x 14" (43 x 20 x 35 cm)

Kit Shipping Weight  

9 lbs (4 kg)


Extruded Aluminum, wall thickness .09" (2.3 mm)


9-Volt Alkaline (> 45 continuous hours use)

Distance of Reception    

Up to 150 feet (45 m)

Sensitivity Threshold    
Minimum Intensity: 10-12 W/m2 (0 dB SPL)

Minimum Ultrasonic Pressure: 2.0 x 10-5 PA @ 40 kHz   

Frequency Bandwidth  

1.8 - 2.2 kHz @ level 0.7 (or -3 dB SPL)  

Working Resonance Frequency  

40 kHz +/- 1.5 kHz

Operating Temperature Range  

-4° to +130° F (-20° to +54° C)

Industrial Grade/600-Ohm Impedance

21-24 dB External Noise Attenuation        
Over or Behind-the-Head (for use with hardhat)

5-year parts & labor on all manufacturer's defects.

No calibration required.

Requalification of performance (once per year)             

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