Since 1924, Sentry Equipment has been dedicated to protecting the people, products and environments that matter the most. In those nearly 100 years of sampling expertise, we’ve been responsible for many "firsts," including:

Compact helical coil sample coolers | Adjustable ultra-high-pressure reducers
Radiation-shielded sampling stations | Non-coring needle samplers

1924 - The Henszey Company

Sentry Equipment started as The Henszey Company making power plant components and milk evaporators for the Carnation Company.

1959 - Sentry Equipment

Dick Henszey bought the family business and renamed it Sentry Equipment because our products “guarded” material integrity and boiler system corrosion. The company was restructured to focus on sampling products and specialty heat exchangers for the power generation industry. This effort not only drove expansion into other industries, but also was key to engineering and manufacturing complete steam and water analysis systems used to monitor water pH in power generation.

1965 - Sentry Sampling Systems

The first Sentry-built sampling systems were ordered by Potomac Electric for their Chalk Point (MD) station. Subsequent state-of-the-art sampling systems received ample publicity and established Sentry Equipment’s long-standing leadership in sampling systems.

1980 - Post-Accident Sampling System

Sentry Equipment developed the Post-Accident Sampling Systems (PASS), designed to allow operators to take manual samples after a nuclear accident.

1986 - Employee Ownership

Company ownership was transferred to the employees through an Employee Stock Ownership Plan (ESOP), leading the way for Sentry Equipment to become 100% employee owned.

2003 - Acquired Bristol Equipment Company

The acquisition of Bristol Equipment, with its well-respected reputation in the industry, added liquid, slurry and powder sampling to our portfolio with the ISOLOK automatic sampling line.

2005 - Acquired Gustafson Automatic Samplers

Purchased from Bayer CropScience, the Gustafson samplers added bulk solids sampling to our portfolio. Including granules, flakes, powders, pellets, these samplers serve a range of industries including cement, chemical, plastic, agriculture and food. This addition created the most comprehensive line of sampling products for process applications in the world.

2007 - New Headquarters Building

Due to acquisitions and organic business growth, Sentry Equipment was bursting at the seams. A new facility was designed and, in August of 2007, the entire company was relocated to the 62,000 square-foot facility located 3.5 miles from the original.

2010 - Acquired AquatiPro Water Chemistry Services

Acquiring AquatiPro Water Chemistry Services meant serving our power generation customers with a multi-vendor service organization to maintain and support all brands of water quality instrumentation, analyzers and sampling equipment. The AquatiPro services - now offered as ProShield Lifecycle Services - help circumvent the challenges caused by unplanned downtime, maintenance, and repairs related to water cycle chemistry processes within power generation plants.

2011 - Acquired Waters Equipment

The acquisition of Waters Equipment from Neptune Chemical Pump Company, Inc. significantly expanded the Sentry portfolio of steam & water sampling solutions. Together, the Sentry and Waters Equipment product lines offer the highest degree of expertise related to the application, design and manufacturing of sampling systems and products.

2013 - Acquired Accurate Tool Company

The addition of products from the Accurate Tool Company created the Sentry Corrosion Monitoring portfolio to monitor corrosion, inject chemicals and extract gas and liquid samples from pipelines.

2014 - Robotic Welder

Automating repetitive tasks with a robotic welder increased the manufacturing efficiency of our standard products and leaves our talented welders free to focus on more complex and customized welding tasks.

2015 - Magnetic Trap

High customer interest in isolating magnetite particulates to protect sample conditioning and analytical instruments made the Sentry Magnetic Trap an overwhelming success.

2017 - Process Monitoring Tech Center in Houston, Texas

To meet the demand of Refining & Petrochemical customers, Sentry Equipment acquired Cobra Sampling, Inc. - a gas and liquid sampling and comprehensive service provider based in Houston, Texas -  and a Gulf Coast service organization providing comprehensive maintenance of sampling equipment in the oil refining and petrochemical industries. These purchases established the Process Monitoring Tech Center (PMTC), a center of excellence to better meet customer demand with a wider portfolio of closed-loop, low-emission samplers, process application expertise.

2018 - GuardSA Smart Chemistry Alarms

To provide power plant operators with the real-time information they need to manage water chemistry, Sentry engineers developed the GuardSA smart alarms, providing operator guidance on the nature of problems and customized troubleshooting advice.

2019 - Acquired Integrity Measurement and Control (IMC)

As a major distributor of Sentry Corrosion Monitoring product lines, the acquisition of IMC helped Sentry Equipment establish closer relationships with our upstream oil and gas customers.

2019 - Cooler City

A game-changing manufacturing technology project dubbed “Cooler City” integrates a laser cutting machine, press brake and milling machine into a highly automated work cell to produce cooler components.