Asphalt is made by heating it to temperatures between 300°F and 350°F to decrease the viscosity and make it more fluid, then drying it to remove any remaining moisture. These temperatures and how the product is processed often require a custom asphalt sampling solution to meet fiscal and personnel concerns.

These concerns are compounded during the paving and installation process, as it must remain hot. This “hot mix” is the most common type used due to its flexibility, weather resistance and ability to repel water.

Upon completion, asphalt is evaluated for its quality regarding consistency/viscosity and purity, which are essential elements. These elements ensure the asphalt can be appropriately controlled, transported and used in paving projects. Sampling is a critical step in this process. But manual sampling methods are hazardous due to asphalt’s high temperatures and the possibility of splattering, which could put the operator in danger.

Case Study: Automatic Asphalt Sampling

An asphalt manufacturer approached Sentry Equipment to replace its manual sampling methods with a new way to safely and effectively sample asphalt during manufacturing.

Our sales and application engineers recommended the Sentry ISOLOK SAB automatic point sampler, which provides representative samples of liquids and slurries up to 500°F.

The ISOLOK SAB sampler uses compressed air to force the plunger into the process line to capture a fixed volume of material. Compressed air then acts on the opposite side of the piston to retract the plunger, allowing the sample to drop by gravity into a container.

However, in this instance, the asphalt sampling points were located far from the main plant, where compressed air wasn’t available in this application. Running compressed air lines to the sampling location would not only be cost-prohibitive but would require a compressor to deliver constant pressurization.

The Solution: Safety And Control

To solve the compressed air challenge, the team developed a custom solution that included an actuator that uses electricity – instead of compressed air – to operate the ISOLOK SAB sampler. A Sentry SBC controller was linked to the sampler to control the sampling logic.

The controller in this application features both Local and Remote operating modes, making it easy to sample the asphalt mix along the process line automatically.

Local mode allows the operator to obtain a single grab sample or continuous samples without any other input. It offers a dry contact interface for remote starting and stopping of the sampler and relay outputs for running the sampler and status alarms.

The Result: Safe and Easy Automatic Sampling

Together, these solutions and expertise turned a complicated situation into a customized solution that easily allowed the plant to implement automatic sampling. The result allowed the customer to receive the following benefits:

• The automatic ISOLOK sampler simplified the entire sampling process while eliminating risks to operators from manual sampling
• The electric actuator avoided the need for running compressed air to the sampling location – saving the plant a significant amount of money to install air lines and a compressor
• By using a Sentry controller, they added a level of control and safety to their process

Not every challenge allows you to use a cookie-cutter solution. Sentry Equipment has the experience and expertise to develop strategic, out-of-the-box solutions that help plants save money, enhance operator safety and maximize equipment operation.

Have a complicated sampling situation? Contact us at +1-262-567-7256 or complete our online contact form to discuss how Sentry automatic sampling systems can help you achieve results.