Ronnie Brown

By: Ronnie Brown on January 6th, 2022

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A Review of the RO-TAP® RX-812 Mechanical Sieve Shaker

Ro-Tap Sieve Shakers

The particle size analysis industry is based on precision, accuracy, and repeatable results. Those that work within it know the road to accurate and repeatable results is sometimes long and daunting.

To help, manufacturers of particle analysis equipment have developed variants of existing devices known to perform, such as sieve shakers. W.S. Tyler is no different as we offer seven sieve shaker variants, such as the W.S. Tyler RO-TAP® RX-812, each designed to accommodate specific test sieve analysis environments.

As particle analysis pioneers that have led the industry for over 140 years, W.S. Tyler understands that finding the right equipment to use is a significant piece to the puzzle when developing the perfect lab setting.

To ensure you understand the bottom line of whether or not the RO-TAP RX-812 is right for you, the article will encompass:

  • What an RO-TAP RX-812 is
  • How much the RO-TAP RX-812 costs
  • The specs of the RO-TAP RX-812
  • How the RO-TAP RX-812 works
  • The pros surrounding the RO-TAP RX-812
  • The cons surrounding the RO-TAP RX-812


What Is the RO-TAP RX-812?


The W.S. Tyler RO-TAP RX-812 is a straightforward sieve shaker that relies on a singular mechanical orbital motion. This entails the machine revolving the sieve stack in a circular motion without the brute force tapping that occurs with other RO-TAP mechanical sieve shakers.

To that end, the lack of hammer taps restricts the RO-TAP RX-812 to particles 100 mesh and larger. This is due to the fact that particles finer than 100 mesh require the additional hammer agitation in order to successfully separate and find the openings of the sieve.


How Much Does It Cost?

The RO-TAP RX-812 is the most cost-effective sieve shaker in the RO-TAP family, standing at approximately $1,731.99. Having said that, this price solely reflects the device.

In other words, any test sieves needed will increase the cost of the order. This is because, contrary to popular belief, test sieves are sold as a separate instrument are not included with the purchase of any RO-TAP model.


What Are the Specs?

  • Footprint: 23" wide x 15" deep x 31.5" high (59cm x 38cm x 80cm)
  • Weight: 55 lbs. (25 kg)
  • Shipping Footprint: 25" wide x 19" deep x 15" high (64cm x 49cm x 38cm)
  • Shipping Weight: 95 lbs. (28 kg)


Available with 115v (60Hz), 230v (60Hz), 115v (50Hz), or 230v (50Hz), the RO-TAP RX-812 provides unique versatility. This is because it is designed to house both eight and twelve-inch test sieves using a sieve adapter.

In addition to the variating voltage options, it should be known that all RO-TAP RX-812 devices are wired with single-phase current.

With eight-inch sieves, this entails six full heights sieves or 13 half-height sieves. With 12-inch sieves, this entails four full-height sieves with a collection pan, six half-height sieves with a collection pan, or eight half-height sieves without a collection pan.



The RO-TAP RX-812 uses a mechanical motor to agitate the sieve stack in an orbital motion. This forces the particles on the sieves to move in a flat plain and make their way through the mesh openings larger than the particle's diameter.

With that, 60Hz units will oscillate 280 times per minute, with 50Hz units oscillating at 231 times per minute.

To that end, the operation duration can be set using a digital timer similar to the RO-TAP RX-29/RX-30. With the RX-812, particles can be tested for up to 99 minutes.

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What Are the Pros?

A major advantage associated with the RX-812 it remains fairly quiet during operation. This is mainly due to the lack of hammer taps seen with other RO-TAP devices.

Having said that, comparable devices such as the RO-TAP RX-29 can reach decimals of 85db (78db when paired with a sound enclosure).

Another noteworthy benefit seen with the RX-812 is that, as its unique orbital motion requires minimal moving parts, operation is less taxing on the equipment resulting in a longer lifespan. As a result, the RX-812 requires fair less maintenance over time when compared to other shakers that utilize brute force sieve stack agitation.


What Are the Cons?

With the RO-TAP RX-812, you are limited in the particle size range that can be tested accurately. Additionally, the minimalistic movement cannot break down any particle agglomeration.

If you have large samples of fine materials, the machine simply can't screen the particles once you reach the 100 mesh threshold. Even some of the coarser materials need the agitation of the brute force hammer taps.

The fact of the matter is lab managers often turn to it because it's a cheaper option. In most cases, however, the extra agitation provided by the hammer is needed to obtain accurate and repeatable results efficiently.


Are You Using the Right Sieve Shaker Type?

The W.S. Tyler RO-TAP RX-812 is a mechanical sieve shaker known for its quiet, easy-to-use operation. While it is quieter and easier to maintain than other RO-TAP devices, the RX-812 limits the particle size range that can be tested confidently.

Now, if you are considering the RO-TAP RX-812 after weighing in the pros and cons, odds are the quiet operation is appealing to you. Well, if that is the case, you may want to also look into the possibilities of electromagnetic sieve shakers as they offer the same low decimal operation.

W.S. Tyler has been a prominent leader of the particle analysis industry for over 140 years and is here to help guide you to accurate and repeatable results you can be proud of.

And with that, we put the following article to shed light on how mechanical sieve shakers, much like the RO-TAP RX-812, compare with electromagnetic sieve shakers:

About Ronnie Brown

Ronnie is the Content Writer for W.S. Tyler and has four years of experience as a professional writer. He strives to expand his knowledge on all things particle analysis and woven wire mesh to leverage his exceptional writing and graphic design skills, creating a one-of-a-kind experience for customers.