Web Tech AutoWeigh and MasterWeigh servicing

Do you service Web Tech and AutoWeigh belt weighers?

Yes, and it is regular work for us. We are an independent service company, not a Web Tech AutoWeigh agent, and we look after the complete scale: the weigh frame and its pivots, the load cells and cabling, the speed sensor, the Masterweigh integrator, and the calibration that ties them together. Web Tech weigh frames and Masterweigh integrators, including the Masterweigh 6, are all part of the same job. Because we work on every major brand, a mixed-brand site is normal for us.

What Web Tech equipment do we see on Australian sites?

Web Tech AutoWeigh is an Australian company, and its gear has a long install base here. We see it most on older Queensland and New South Wales coal operations, though it turns up right across the country. A good number of the frames are decades old and still perfectly serviceable, which is a good reason to keep them running.

Web Tech weigh frames are modular units that bolt into the existing conveyor structure, and they run from single idler process scales up to multi-idler frames where the site needs tighter accuracy. Which one is in front of you, and how many idlers it weighs over, changes the calibration, so identifying it correctly is the first step on any job. On the integrator side, the Masterweigh range is what we most often meet driving these frames. We see the older Masterweigh 1 and 5 units still working away, the Masterweigh 6 on a good number of sites, and the newer Masterweigh Novus on more recent installations.

Why do we measure every Web Tech frame instead of assuming standard dimensions?

This is the single most important thing to get right on a Web Tech scale, and it is where an assumed setup goes wrong.

The calibration on these frames is proved with static weights, calibration bars placed on the frame, and the target the integrator should read from those bars is worked out from the physical geometry: where the pivot sits, the idler spacing, the distance from the pivot to the load cell, and where the calibration weights bear. Get that geometry right and the target is right. Get it wrong and the scale is off before the belt has even turned.

The trap with Web Tech frames is that many were built with custom idler spacing rather than one fixed standard. Assume a typical spacing when the real frame was built to a different figure, and the calibration target is wrong from the outset, so the scale reads off by that same ratio no matter how carefully you run the rest of the calibration. So we measure the actual frame every time, confirm the configuration and the real dimensions, and work the target from what is physically there. It costs a few minutes on site and saves chasing a reading error that was baked in at setup.

What does a Masterweigh calibration actually involve?

At a reader level, a Masterweigh calibration follows the same logic as any belt weigher, in 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 routine re-check we want that zero small, a fraction of a percent, and if it has drifted we find out why: build-up on the frame, a seized idler, a tie rod touching, or moisture in a junction box.

Second, span. This proves the scale against a known load using the static calibration weights on the frame. Because their effect depends on where they sit relative to the pivot and load cell, we match the target to the frame geometry we measured, then apply the weights and confirm the integrator reads it.

Third, a material comparison where it is warranted. The final trim is a check against a separately weighed load, a truck or train weighed both ways. If the scale and the weighbridge disagree by a steady amount, we bring the two together without disturbing the zero and span. Every value we change is recorded as found and as left, so the next tech can see what state the scale was in. This is maintenance calibration to keep the scale honest for production and stock reconciliation, not a trade-measurement certificate. Those figures go into AIMM, our asset management system, so every Web Tech scale we look after has a permanent record and a due date you can see, at no extra cost.

What faults do we see most often on Web Tech scales?

A few come up again and again, and most are shared with every other brand rather than being specific to Web Tech:

• Aged frames and rollers. Older frames earn their keep, but pivots wear, tie rods can bind, and material builds up on the carriage. Each of these upsets the zero, so they are the first things we check on a scale that has drifted.
• Load cell cabling and junction boxes. A load cell speaks in millivolts, so a corroded terminal, moisture in a box or a rodent-chewed cable will shift the zero and make the reading wander. Older installations are prone to all three.
• Speed sensor wear. How the speed is picked up varies: some installations use a wheel riding on the belt, but plenty drive the sensor from a pulley or shaft, often an encoder on the tail pulley. Either way the moving parts wear, and a seized or noisy bearing on a wheel type is one of the most common speed faults we find. When a sensor is swapped we check that the replacement’s output type and signal level suit what that integrator’s speed input will accept, then re-run the pulses per belt revolution check before the scale goes back into service, because a different sensor changes that figure.

For the full run-down of faults across all brands, see common belt weigher faults, and for sensor selection and troubleshooting in detail, see our belt weigher speed sensors guide.

Why use an independent for a mixed-brand site?

We are an independent belt weigher service company, and for most sites that is an advantage.

The same service technicians for every brand. Few plants run a single make of weigher. When one company can calibrate your Web Tech AutoWeigh scales alongside every other brand on site, you get one team of service technicians and one schedule.

Spare parts for every brand. We supply spare parts for Web Tech equipment 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.

Straight condition reporting. We look after these scales, so when a frame is genuinely worn or a scale sits where it will never weigh well, we say so and set out the options. Just as often the honest answer is that an older frame has years left in it.

Field-first knowledge. Everything here comes from calibrating these scales on real sites, on Web Tech weigh frames and Masterweigh integrators, and on every other brand, so we are not tied to one product line.

Replacing an integrator. Where a Web 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.

Frequently asked questions