The Pioneer of Modern Leak Testing

Uson 628 Differential Pressure Decay Leak Tester

A highly sensitive, budget-friendly leak tester that helps you reduce product deviations or recall issues through early identification of leaks

Uson 628 Differential Pressure Decay Leak Tester

An easy-to-use differential pressure decay leak tester designed to deliver clear, non-subjective results at a level of performance expected from more complex and expensive instruments

Uson’s 628 differential pressure decay leak tester is a compact, reliable, and accurate instrument that is ideal as a budget-friendly benchtop option for a wide range of industries. The 628 leak tester incorporates an intelligently designed multi-language user interface, with the capability to collect and transmit a vast amount of data, for offline trend analysis and a deep level of insight.

The 628 is a highly flexible leak tester, offering users the ability to choose from five pressure ranges – from vacuum up to 225 psi (15 bar) to cover a wide range of applications, making it useful for a wide range of industries and applications. And, it allows users to create and save up to 30 test programs, which can be created and stored in the instrument’s memory for fast recall of test parameters.

Download Brochure    628 Data Sheet

The 628 easily accommodates multiple test pressures

For applications that need to test a multiple test pressures, the 628 offers an optional electronic regulator. With the electronic regulator option, the 628 can be programmed to test a part at different test pressures in a sequence. Additionally, the test programs can be linked, serving to further the automation of the test sequence. Another benefit with the electronic regulator is that it adds an increased level of security. It is only accessible through the programming interface and can be locked and safeguarded to prevent unintended changes. This is a significant advantage over a manual regulator, which can be adjusted from the back of the instrument.

The 628 leak tester is easy to use and requires minimal operator training

The 628 leak tester was designed to be easy to use in a busy environment. A backlit user interface makes accessing information easy, while bright uniquely designed lights on the front panel allow for at-a-glance monitoring from across a room. The menu system is intuitively structured to make setup and operation practically effortless.

Reliable performance, with accurate results every time

The 628 leak tester is a surprisingly powerful instrument, packaged in a simple design. Incorporating the differential pressure decay method to provide highly accurate and reliable results, the 628 can run test cycles to display leak rates in a range of pressure units or volumetric units using the leak rate calibration option. The 628 incorporates Uson’s industry-proven proprietary sensor and valves, to deliver the type of results that are expected from more sophisticated instruments.

Access to an extensive amount of information to help you manage your process

The 628 leak tester ensures a high level of control over the instrument. With a convenient USB port, firmware updates, data transfers, and program backups are easy. Program security and data access are controlled by a password, while couple safety valves control the position of the machine in the event of a power failure.

Designed to meet the highest standards of quality and performance

With a durable, splash-proof and dust-proof enclosure, the 628 leak tester is designed for quality in manufacturing laboratory environments. It features a reliable, solid-state hard drive for high-speed data transfer, and accommodates single-range 0-20 mbar calibration for accurate results. Plus, the 628 features an advanced, upgrade friendly design that makes service and maintenance easy.

Model 628 Specifications

Leak Rate Measurement

Sensor Type Capacitive differential
Range 20 mbar/2000 Pa/0.29 psig
Resolution 0.01 mbar/1 Pa/0.0001 psig
Accuracy ± 1% range

Test Pressure Measurement

Sensor Type Solid State
  • -950 mbar/-95 kPa/-14 psig
  • 1 bar/1000 kPa/15 psig
  • 4 bar/400 kPa/60 psig
  • 10 bar/1000 kPa/150 psig
  • 15 bar/1500 kPa/225 psig
Resolution 0.01 mbar/1 Pa/0.0001 psig
Accuracy ± 1% of gauge pressure range

Leak Test Medium

Compressed Air
Contact factory for other media.

General Specifications

Number of Programs 30
User Interface
  • Display, LCD, 4.3”
  • Start & Reset buttons
  • Tactile programming keys
  • Pass/Reject LED light bars
Interface Serial, External I/O Control, and USB
Supply Input 24 VDC
Air Supply
  • Clean, dry air, 4-15 bar
  • (60-225 psig)
Dimensions (H x D x W) 5.3 x 12.6 x 13.2 inches (134 x 320 x 335 mm)
Weight 22 lbs. (10kg)
Pressure Units psig, bar, mbar, Pa, kPa, kgcm2, mmH20, cmH20, inH20, mmHg, cmHg, mHg
Manufacturing Standards
  • ISO 9001:2008
  • Certified to CE requirements
  • RoHS
  • WEEE


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Fax: +1-281-671-2001


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