About us

About Sentry

Safeguarding People and Processes

A healthy global society needs industry to perform at its very best, and that is why Sentry Equipment is committed to protecting it. Guided by a constant desire to do more, we hold ourselves accountable to and responsible for people, processes, and the planet for a safer world. What we do with engineering, we do with ourselves. We make things better together. 

Integrity and Respect

"Do the right thing," is a phrase that echoes throughout Sentry Equipment. Each employee owner is committed to upholding their promises, focusing on our customers needs above our own, and respecting every individual we interact with daily. It goes beyond a moral obligation, it is an act of doing business.

Positive Environment

Our leadership recognizes we are humans first and our title second. By focusing on getting to know each other, we gain a level of camaraderie that fosters a positive environment and brings joy to our work.


At Sentry Equipment, we try to be as fair as possible. Our employee owners our committed to providing a result in which everyone can be proud. This requires compromise, open and honest discussions, and collaboration to meet our end goals.

Customer Driven

Our experience may define us, but our customers define our innovation. Every project we undertake should only work one way - yours. This allows our team to not only share in customer success but also take accountability when things don’t go quite right. We choose to be allies in our customer’s needs.   

Owned and Operated in the USA

As 100% employee owners, we are proud to be operating, manufacturing, and working throughout the USA. 

Established in the Milwaukee area, we have expanded to other key locations throughout the United States. Our Oconomowoc location acts as a key manufacturer of the majority of our sampling and process improvement products. This location acts as our headquarters and drives our commitment to revitalizing and redefining manufacturing in Wisconsin. 

Meanwhile, our Houston location is our manufacturing and service hub for all oil and gas application needs. Finally, our Salt Lake City location provides manufacturing and service expertise for our water/wastewater products. 

Each location's expertise is critical to our customer's success and we regularly all work together to ensure the best outcome for each order. 

A History of Continuous Improvement

For over 100 years, Sentry Equipment has been driven by one simple purpose – doing what is best for people and processes. Each innovation, strategic acquisition, and milestone has been driven by our customers’ best interests and the future of the world’s infrastructure. Follow the journey that has shaped Sentry Equipment into the partner we are today.

  • 1925

    Sentry Equipment Established
    Sentry Equipment Established

    Established as the Henszey Company, Sentry Equipment began their legacy by creating power plant components and milk evaporators.

  • 1959

    Henszey Company Becomes Sentry Equipment

    In response to industry and customer needs, the Henszey Company diverts their focus on supporting the power generation and rebrands accordingly.

  • 1965

    Developed the First Sampling System
    Developed the First Sampling System

    Sentry designed, manufactured, and installed the world’s first complete sampling system for Potomac Electric in their Maryland plant.

  • 1980

    Created Revolutionary Safety Standards
    Created Revolutionary Safety Standards

    Due to widespread nuclear power usage, Sentry Equipment created the Post-Accident Sampling System (PASS) to ensure safety during manual sampling after a nuclear incident.

  • 1986

    Sentry Employees Become Owners
    Sentry Employees Become Owners

    Dick Henszey retires and transfers ownership to his employees through an Employee Stock Ownership Plan (ESOP), leading the way for Sentry Equipment to becoming 100% employee owned.

  • 2003

    Bristol Equipment Joins Sentry Equipment

    Sentry Equipment purchases Bristol Equipment, expanding into liquid, slurry, and powder sampling with the ISOLOK product line.

  • 2005

    Gustafson Samplers Enhance the Bulk Solid Sampling Line

    Purchased from Bayer CropScience, the Gustafson product line allowed Sentry Equipment to expand their expertise into other industries such as cement, chemical, plastic, agriculture and food.

  • 2007

    Sentry Equipment Expands their Operations
    Sentry Equipment Expands their Operations

    Renewing their commitment to the Oconomowoc area, Sentry Equipment builds a 62,000 square foot, state of the art facility focused on safety and future growth.

  • 2010

    Aquatipro Expands Sentry’s Sampling System Capabilities

    By acquiring Aquatipro Water Chemistry Services, Sentry Equipment not only expanded their system offerings but also added our robust service capabilities, now known as ProShield Lifecycle Services.

  • 2011

    Sentry Equipment Obtains Waters Equipment Systems

    Through the acquisition of Waters Equipment, Sentry Equipment cemented their complete sample system capabilities through improved design and manufacturing.

  • 2017

    Sentry Equipment Adds a Location
    Sentry Equipment Adds a Location

    Sentry Equipment created their first satellite location in Houston through the acquisition of Cobra Sampling. This added training and services for refineries in the area.

  • 2019

    Big Changes Come to Sentry Equipment

    Sentry Equipment acquired Integrity Measurement and Control (IMC) to expand their corrosion monitoring line and committed to manufacturing excellence by investing in over $1 million of equipment.

  • 2022

    Renewed Commitment to Infrastructure
    Renewed Commitment to Infrastructure

    Sentry Equipment acquired SmartSkim, a leader in oil separation, and Rebuild-it Services Group, a wastewater clarifier team, and created a new satellite location in Salt Lake City.

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Ownership Unlocks Potential

Employee ownership is more than a business structure, it’s a way of life. Explore how ownership makes a difference at Sentry Equipment.

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Putting in our A-Game

Every day we are driven to succeed by the challenges we seek. This requires our employee-owners to hold ourselves to a higher standard. At Sentry Equipment, we define these as A-Player competencies. These A words guide our decisions, our culture, and our integrity in everything we do.