Thermo Ramsey belt scale and Micro-Tech servicing

Do you service Ramsey and Thermo belt scales?

Yes, and it is a large part of what we do. The Micro-Tech 9101 is one of the most common integrators we see on Australian sites, and we look after the whole scale: the weigh frame and its pivots, the load cells and cabling, the speed sensor, the integrator, and the calibration that ties them together. Because we work on all brands, a mixed-brand site is normal for us.

What is the imperial-units trap, and how do we avoid it?

The Micro-Tech 9101, 3101 and 2001 family was designed in the United States, and most of its manuals and factory setups work in imperial units: inches and pounds. We work in metric. Where a unit can be switched we set it up in metric, and where it cannot, we convert every figure ourselves, so every number we record and report is in millimetres, kilograms and tonnes.

The classic commissioning mistake is a mixed-units entry: one dimension left in millimetres while the rest are in inches. Nothing on the display shouts an error. The scale simply reads wrong, sometimes by a little and sometimes by a lot, and it is slow to track down if you did not set it up yourself. We cross-check every dimension against the frame before we run a calibration.

What are scale codes, and what happens when the data plate is missing?

The heart of a Micro-Tech setup is the physical geometry of the weigh frame: where the pivot sits, how far the load cell and each weigh idler are from it, the idler spacing, and where any test weight hangs. Thermo grouped the common frame geometries into numbered scale codes, so a technician could enter one code instead of typing every dimension.

The problem on older frames is that the data plate carrying that code is often gone: painted over, corroded off, or no longer valid because the frame has been modified. When that happens, we measure the frame geometry ourselves and work back to the matching scale code, or enter the true dimensions as a custom setup. Getting this geometry right matters more than almost anything else: it sets the lever ratio the whole calculation depends on, and a small error carries straight through to every tonne the scale reports.

What does a Micro-Tech calibration actually involve?

A routine calibration has three parts.

First, zero. We run the belt empty at its normal running speed and let the integrator average the empty-belt load over several complete belt revolutions, not just a few seconds, so a lumpy or uneven belt averages out. On a new setup we accept the resulting zero error. On a routine re-check we want it small, a fraction of a percent, and if it has drifted further we find out why: material on the frame, a seized idler, a tie rod touching, or water in a junction box.

Second, span. This proves the scale against a known load, done either electronically with R-Cal (an internal reference that simulates a load) or physically with calibrated test weights on the frame. As with zero, we hold to a tighter figure on a routine check than on a first setup.

Third, the material factor. The final trim is a comparison against a weighbridge: a truck or train weighed both ways. If the scale and the weighbridge disagree by a steady amount, we apply a material factor to bring the two together. This is routine maintenance calibration to keep the scale honest for production and stock reconciliation, not a trade-measurement certificate.

Can you keep an old Micro-Tech running?

Usually, yes, and often for years yet. A well-kept 9101 will run for decades. The parts that age are the memory-backup battery, the display and the keypad. The battery matters most: if it goes flat and the site loses power, the integrator can lose its whole configuration, which means a full recommission if nobody wrote the settings down.

That is why we keep a record of every integrator’s working parameters. A 9101 holds around nineteen of them (scale capacity, revolution timing, the load cell millivolt readings at zero and span, weigh span, belt speed and length, and the test values), so if a unit loses its memory we can reload it rather than start from nothing. Those records live in AIMM, our asset management system, alongside the calibration history and the date the next service is due.

When does replacing it make sense? Honestly, less often than you might be told. If the unit still holds its calibration, still talks to the plant, and spares are available, there is no reason to change it. We would suggest a newer integrator when a board has failed and spares have dried up, when you need features the old unit cannot offer such as data logging or network comms, or when a site is standardising. Either way you get a straight answer, not a push to buy new hardware.

What faults do we see most often on Ramsey scales?

A few come up again and again:

• Mixed units after a partial re-setup. It is the first thing we check on a scale that has always read a little off.
• Aged load cell cabling and junction boxes. A load cell speaks in millivolts, so a corroded terminal, moisture in a box or rodent-chewed cable will shift the zero and make the reading wander. Older installations are prone to all three.
• Speed sensor wear. The spiral cage wheel that rides on the belt lives on its bearings, and a seized or noisy bearing is the single most common speed fault we find. The 9101 is easy-going on the electrical side: it is happy with a proximity sensor, NPN or PNP, over a wide frequency range, so the signal is rarely the limit. It is the mechanical side, the bearing, the spring pressure and the belt contact, that wears out.

When a scale reads wrong and the cause is not obvious, we can work back from the integrator’s raw A/D counts against the load cell millivolt output to tell whether the electronics are counting correctly or the fault is mechanical. For the full run-down of faults across all brands, see common belt weigher faults.

Why use an independent for your Micro-Tech scales?

We are an independent belt weigher service company. We are not Thermo Fisher, and we do not pretend to be. What we bring is people who have spent years on these exact integrators and frames, and on every other brand on site, so we are not tied to one product line. We carry the field knowledge and the test gear to set up, fault-find and calibrate a Micro-Tech properly.

New hardware still under warranty is the one case to check with whoever supplied it before anyone else touches it. For the ageing 9101s and 10-series frames doing the daily work on Australian sites, an independent who knows them well is usually quicker to site and able to look after the rest of your scales on the same visit.

Replacing an integrator. Where a Micro-Tech integrator is beyond economic repair or no longer supported, a Schenck or EMC integrator — we are an agent for both — can in most cases be fitted to your existing weigh frame. Ask us before you replace anything, because the answer depends on the frame, the load cells and how the site is wired.

We supply spare parts for Ramsey and Thermo belt scales, Micro-Tech integrators and every other major belt weigher brand: the genuine part where the maker makes it freely available, and an equivalent we know works where a maker keeps its parts for its own technicians. Availability and lead times can vary for older or discontinued models.

Frequently asked questions