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Image by American Public Power Associati



000045 Standard Model

The UL101 Electrical Inspector utilizes airborne attachments to safely inspect sealed electrical panels and substations. The UL101 Electrical Inspector allows for early, long-distance detection of arcing, corona discharge, and tracking. Save time and money by reducing transmission/distribution loss and outages. The parabolic accessory (PowerBeam 300) can accurately pinpoint sources of ultrasound within 1 degree off target from up to 300 feet (91.44 meters) away. 


Benefits of UL101 Acoustic Ultrasound Listening Devices


Simply adjust the sensitivity on the UL101 Electrical Inspector'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 Electrical Inspector 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. 


Electrical Inspection 
(Power Transmission and Substations, Electric Panels, MMCs, etc)

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

Key Features

  • Fixed Frequency

  • Double the sensitivity of other parabolic dishes

  • Easily adjustable sensitivity and gain

  • Converts ultrasound to easily recognizable audible sounds

  • Standard 9-Volt Battery for UL101 Receiver

  • Two AAA Batteries for PowerBeam 300 (powers laser pointer)

  • "Rifle Site" to pinpoint when outdoors

  • Laser to pinpoint when indoors

  • Inspect sealed panels without opening or using an expensive window

  • Identify arcing and tracking potential as a safety precaution before using infrared

UL101 Ellectrical Inspector in use

Technical Specifications

PowerBeam 300 Dimensions

21" x 17" x 1.26" (533 x 432 x 32 mm)

Dish Diameter         

13" (330 mm)                          
PowerBeam 300 Weight

45 oz (1.3 kg)  
PowerBeam 300 Power Supply

Two (2) Standard AAA Alkaline Batteries (for laser)
Battery Life

> 20 hours
PowerBeam 300 Warranty

1 Year Parts & Labor
Receiver 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)
Receiver Weight

11.6 oz (330 g)

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

9-Volt Alkaline (> 45 continuous hours use)
Kit Shipping Dimensions    

21" x 18" x 7" (53 x 18 x 46 cm)
Kit Shipping Weight    

14 lbs (6 kg)
Distance of Reception

Up to 300 feet (90 m)    
Sensitivity Threshold    

Minimum Intensity: 10-12 W/m2 (0 dB SPL)Minimum Ultrasonic Pressure: 2.0 x 10-5 PA @ 40 kHz        
Working Resonance Frequency    

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

UL101 Electrical Inspector Technical Specifications
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