Bulk Solid Samplers for Representative Dry Material Sampling

Improve Sample Accuracy | Automate Quality Control | Increase Process Confidence

We help identify and implement the right Sentry bulk solid sampling solution for powders, pellets, granules, seeds, flakes, grains, and other dry bulk materials. From gravity chutes and hoppers to screw conveyors, drag conveyors, and pneumatic conveying systems, Sentry samplers deliver representative samples that improve quality control and process reliability.

Get a Bulk Solids Sampling Recommendation

Automatic and manual bulk solid samplers for powders, granules, pellets, grains, plastics, food ingredients, chemicals, minerals, cement, agriculture, and dry bulk material handling applications.

Sentry Model RPG Sampler

Automate point sampling from a gravity chute or hopper.

Discuss My Application Download Product PDF Technical Information

Automate point sampling from a gravity chute or hopper.

Do you need a retracting sample chamber for a homogeneous product?

The Sentry RPG inserts a sample probe into a gravity stream, rotates its chamber to collect material, then retracts and turns the chamber for discharge. It is a point-sampling design for suitable dry, free-flowing material.

Typical application
Take scheduled increments from a well-mixed granular ingredient leaving a hopper.

Also known as: Automatic point sampler, rotating-chamber sampler, gravity-chute sampler.

What this sampler can help you do

Control the sampling sequence

Coordinate probe extension, chamber rotation, retraction, and discharge.

Withdraw after collection

The probe retracts from the process stream between sampling cycles.

Match the reach to the line

Select the stroke and mounting arrangement around the chute or hopper geometry.

How the sampling cycle works

Extend the probe

The pneumatic cylinder moves the chamber into the process stream.

Rotate to collect

At extension, the rotary actuator turns the sample chamber upright.

Retract and discharge

The tube retracts and the chamber rotates down to release material to the collection point.

Materials & industries to review

Food & ingredient powders

Dry, free-flowing powders or granules with suitable homogeneity at the sample point.

Flakes & pellets

Review particle dimensions, breakage sensitivity, and whether the chamber fills and empties consistently.

Industrial dry products

Suitable free-flowing chemical or mineral products in gravity transfer, with wear and seal compatibility reviewed.

Sampling-method overview

Compare Sentry’s bulk-solids sampling methods

This official Sentry overview explains the wider solid-and-powder sampler range. Use it to compare point, strip, and cross-cut approaches before discussing an RPG installation. It is a range overview, not a dedicated RPG demonstration.

Watch on Sentry Equipment’s official YouTube channel

Review the sampling point and collection path

Check that the selected point sees a homogeneous product through the production run. Review the probe reach, the chamber’s filling and discharge, access for service, and how the sample reaches its container without retention.

Dimensional inspection of a Sentry bulk-solids sampler component — Sentry manufacturing: dimensional inspection of a bulk-solids sampler component. Photo: Sentry Equipment.

Document your material properties, process conditions, and required sample quantity with Sentry’s application worksheet.

Open Application Worksheet PDF

Configuration & selection

Sampling method: Automatic point sampling with a rotating sample chamber.
Process location: Gravity spouts, hoppers, and transfer chutes.
Published particle range: 10 µm to 6 mm for the standard arrangement.
Stroke options: 102, 152, 203, 254, or 305 mm (4, 6, 8, 10, or 12 in).
Process duty: The published specification identifies atmospheric service; compressed air operates the cylinder and rotary actuator.

Options to discuss with RTS

Stroke and mounting adapter
Release coating
QPQ hardening of contact surfaces
Sample-tube purge
Stainless housing and rails
Air preparation, controls, and sample containers

Send a line sketch, material description, particle-size range, bulk density, flow rate, pressure or vacuum, temperature, and cleaning requirements. Include the sample quantity, collection interval, and laboratory test you need to support.

Review My Sampling Requirements

Questions to settle before selection

Is the RPG a strip sampler?

No. Sentry classifies it as a point sampler. Its rotating chamber collects material at a location in the stream. If the product segregates across the chute, discuss a strip or cross-cut method instead.

How often should we take a sample?

Base the plan on the lot or batch, how the material varies over time, the test method, and the required composite quantity. Share the production pattern and analysis requirements so RTS can review the interval and collection arrangement with Sentry.

Can the sample be collected automatically?

Discuss sampler controls, the container location, and individual or composite collection. Confirm the controller and any indexing or collection equipment as part of the quotation; those accessories are not assumed to be included.

PDF Literature & Technical Resources

Use the literature to plan the discussion. Final materials, operating limits, controls, mounting, and installation drawings are confirmed for the selected application.

Compare the Sentry sampler range

Conveyor point sampling

Model A Sampler >>

Take repeatable point samples from a conveyor or gravity chute.

Example: Collect routine quality-control increments from a well-mixed dry ingredient stream.

Also known as: Automatic point sampler, conveyor sampler, sliding-gate sampler.

Free-flowing strip sampling

Model RX Sampler >>

Collect a strip sample across a free-flowing material stream.

Example: Review a flour, granular ingredient, grain, or seed stream where segregation could bias a point sample.

Also known as: Automatic strip sampler, retracting-tube sampler, pneumatic-line sampler.

Gravity-flow point sampling

Model RPG Sampler >>

Automate point sampling from a gravity chute or hopper.

Example: Take scheduled increments from a well-mixed granular ingredient leaving a hopper.

Also known as: Automatic point sampler, rotating-chamber sampler, gravity-chute sampler.

Retracting strip sampling with an auger

Model RB Sampler >>

Take a strip sample and convey it out with an auger.

Example: Review a powder stream where gravity transfer through a sample tube is unreliable.

Also known as: Automatic strip sampler, retracting auger sampler, bulk-powder sampler.

Low-height strip sampling

Model D2 Sampler >>

Sample across a gravity stream with a rotating slotted tube.

Example: Review a gravity chute carrying powder, granules, or suitable kibble where material can segregate.

Also known as: Automatic strip sampler, slotted-tube sampler, D2 SSD sampler.

Fixed-volume point sampling

ISOLOK SAK Sampler >>

Collect fixed-volume increments of powder, flakes, or granules.

Example: Build a composite sample from repeated increments of suitable salt, cement, fertilizer, or food product.

Also known as: ISOLOK automatic point sampler, fixed-volume sampler, plunger sampler.