Amprobe TMULD-300 Ultrasonic Leak Detector with Transmitter

(10 customer reviews)

  • The UT-300 Transmitter transmits an ultrasonic signal for non pressurized applications
  • Tests the “air-tightness” of weather seals, tanks, ovens, refrigerators, etc.
  • Locating leaks in duct work
  • Finds the ends of buried PVC pipes
  • Detects any pressurized gas leak regardless of type CFC’s, HFC’s, Nitrogen, etc. (unaffected by contaminants)
SKU: 2731543 Category:


When leaks occur they often generate an ultrasonic frequency that is beyond human hearing. Amprobe’s TMULD-300 converts these sounds into an audible range for easy detection. The TMULD-300 tests pressurized air lines, refrigeration systems, and steam lines for leaks.

Quickly and easily locate a leak location with this unique device. The TMULD-300 includes an ultrasonic transmitter that is great to use in areas where leaking gases are not sufficiently pressurized. Check for door or trunk seals, windshield leaks. The transmitter creates ultrasonic sound waves for detecting cracks and leaks.


UT-300 Receiver
Operating Temperature 32 °F to 100 °F
Storage Temperature -40 °F to 150 °F
Weight 6.3 oz with battery
Dimensions 7.3 x 2.5 x 1 in
Frequency Response 35 kHz to 45 kHz + 6 db
Power Consumption 22 mA at 9 Volts DC
Battery Life 33 hours (9 V alkaline battery)
Performance Meets the ASTM Standard: ASTM E1211-07
Battery Test LED color indicator (Green-Good; Red-Replace)
UT-300 Ultrasonic Transmitter
Operating Temperature 32 °F to 100 °F
Storage Temperature -40 °F to 150 °F
Weight 5.7 oz with battery
Dimensions 6.5 x 2.5 x 1 in
Frequency 40 kHz
Power Consumption 8.5 mA at 9 Volts
Battery Life 60 hours (9 V alkaline battery)


Amprobe TMULD-300 Ultrasonic Leak Detector with Transmitter Overview

What’s Included

  • UT-300 Receiver
  • UT-300 Transmitter
  • Flexible tubing adapter
  • Tubular extension
  • Carrying case
  • Power parabola
  • Headphones
  • Batteries (installed)


Datasheet »
Product Manual »

10 reviews for Amprobe TMULD-300 Ultrasonic Leak Detector with Transmitter

  1. Marianne57

    This product is great for finding leaks.

    We find leaks in telephone cables. This product is better than any other ultra sonic we have used. We have found leaks in the aerial cables that are 20 feet or more in the air. We have found leaks in the underground manholes that are 8 feet deep or more. This product is reasonably priced and works great.
    We have told many telephone company supervisors about this product.

    ✔ Yes, I recommend this product.

  2. Hank

    Very usefui tool

    My first application for this device was to check the integrity of a sanitizing chamber for hospital operating equipment , we ound the leak and repaired. Next was a set of refrigerant lines about 12′ overhead , with insulation on the suction line , I was able to walk under the lineset and find the problems without removing the insulation or working from a ladder any more than absolutely necessary .

    ✔ Yes, I recommend this product.

  3. bhappy

    A Very Good Leak Detector

    Currently have one of these and use it when I find a flat system just pressurize with nitrogen and it will find the leaks very quickly.

    ✔ Yes, I recommend this product.

  4. scberry

    great product

    This a great instrument for finding small leaks in refrigerant coils.

    ✔ Yes, I recommend this product.

  5. BigLazy

    Retro fitting in older homes

    Some older homes have seen abuse in attics and line entry points. Quick way to locate the smallest leak in tight locations.

    ✔ Yes, I recommend this product.

  6. steelbuilder

    Really useful leak detector

    Used this tool for several leak problems. With the transmitter to find leaks around windows and at stucco edges. Also used to find a leak in the window of my car. Without transmitter, I found it very easy to locate problem valves and fittings.

    ✔ Yes, I recommend this product.

  7. giazpurua

    Great help for HVAC contractors

    Good instrument that really helps you find small leaks. Can be used by itself, or in combination with other tools (electronic sniffer, for example). The only drawback is that instrument and accesories do not seem to be contractor grade, so you must be very careful when using them and take good care of it. It comes in a handy case that helps keep it protected.

    ✔ Yes, I recommend this product.

  8. Bruce


    I love this leak detector, it does not care what refrigerant you are checking and never needs calibration

    ✔ Yes, I recommend this product.

  9. Mark1

    Ultrasonic over 20 years and running

    In the eighties i purhased my 1st ultrasonic at a trade convention. the 100 series. This tool paid for itself many times over. I have found leaks both large and small inside walls , on evaporator coils, condensers and water lines. I’ve loaned it to two colleagues whom purchased your product immediately after using mine. These tools lead the industry in leak detection through its sensitivity and ability to detect negative or positive pressure.. I recently purchased the # TMULD – 300 and it is better than my first, which is still used today.

    ✔ Yes, I recommend this product.

  10. Bbatman

    Works as promised

    This ultrasonic detector works as well as promised. For the cost of it I found it’s well worth the cost and works well for what it’s intended for
    You can spend more money for a unit 10 times as much and then maybe get better results
    I’ve had three people use it and they all agreed it works well

    ✔ Yes, I recommend this product.

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