Loader Scales and Forklift Scales: How Tara MNM Scales Systems Work
Reviewed by MNM Scales technicians · Updated October 27, 2026
Short answer: a loader scale or forklift scale is an on-board weighing system. A pressure sensor reads the hydraulic pressure in the lift cylinder, and an indicator in the cab converts that pressure into weight, so the load is weighed while it is being lifted, with no trip to a floor scale. Tara MNM Scales systems fit front end loaders, forklifts, backhoes and other machines with a hydraulic lift. MNM Scales technicians install and calibrate them on-site, and every system we ship is calibrated before it leaves our shop. Systems start at $979.
Shop Tara MNM Scales systems Call (832) 290-3120 Request an installation quote
Weighing on the machine saves the time it takes to drive every load to a scale and back. The operator lifts, reads the weight, and keeps working. MNM Scales has sold, installed and serviced weighing equipment for over 30 years, since 1992, and the Tara MNM Scales line is our own family of hydraulic on-board systems. This guide explains how a loader or forklift scale works, which Tara system fits which machine, what affects accuracy, and how installation and calibration are handled.
How a hydraulic loader scale works
Every machine that lifts with a hydraulic cylinder already “knows” the weight it is carrying: the heavier the load, the higher the pressure in the lift circuit. A Tara MNM Scales system puts that pressure to work in four parts:
- Pressure sensor (transducer): fitted into the hydraulic line that feeds the lift cylinder, usually with a tee fitting. It sends a small electrical signal that rises with pressure.
- Indicator: mounted in the cab where the operator can see it. It converts the signal to weight, shows it in pounds or kilograms, and keeps running totals.
- Cable and power: the sensor cable runs along the boom or mast to the indicator, which is powered from the machine.
- Printer (on printer models): a small thermal printer prints a ticket for each load or a total for the shift.
Because the reading comes from pressure, the system is calibrated on the actual machine: the technician lifts an empty attachment and a known weight, and the indicator learns the relation between pressure and weight for that machine. That is why on-site calibration, or a calibration on a matched setup before shipping, matters more for a loader scale than for a bench scale.
Tara MNM Scales systems we carry
Prices below are today’s prices on our store (checked October 27, 2026). Each system is calibrated before it ships. Installation on your machine, hydraulic fittings beyond those in the box, and on-site calibration are not included unless the listing says so.
| System | Fits | Printer | Price |
|---|---|---|---|
| Tara system, pressure sensor (TR-1-NK-HE) | Forklifts and loaders | Not included | $979 |
| Tara system, pressure sensor, with printer (TR-1-NK-HE-P) | Forklifts and loaders | Included | $1,399 |
| Tara MNM Scales front end loader scale, bucket loader scale, made in USA | Front end and bucket loaders | See listing | $1,048 |
| Tara MNM Scales forklift, front end loader and backhoe on-board system | Forklifts, loaders, backhoes | See listing | $1,149 |
| Tara system with thermal printer and pressure sensor | Forklifts and loaders | Thermal, included | $1,449 |
| Tara MNM Scales forklift, hydraulic and loader scale with thermal printer | Forklifts, loaders, hydraulic lifts | Thermal, included | $1,499 |
See the full line in our hydraulic scale category, or browse all industrial scales. Not sure which system matches your machine? Call us with the make, model and lift capacity, and we will tell you which kit fits and what fittings it needs.
Loader scale, forklift scale or backhoe scale: what changes
The principle is the same on every machine. What changes is where the sensor goes, how the load moves, and what the operator does to get a repeatable reading.
| Machine | Where the sensor goes | What to watch |
|---|---|---|
| Front end or wheel loader | Lift cylinder circuit (base end) | Bucket position and lift speed; weigh at the same point in the lift every time |
| Forklift | Lift cylinder circuit on the mast | Mast tilt and fork height; weigh with the mast vertical and the load at the same height |
| Backhoe or skid steer | Boom or lift circuit | Arm geometry changes the pressure; use one weighing position and one speed |
What affects the accuracy of an on-board scale
A well-installed hydraulic scale that is used the same way every time gives fast, repeatable weights. Typical on-board hydraulic systems read to within about 1 to 2 percent of lift capacity, and the operator’s routine is a big part of that. These are the factors our technicians check first:
| Factor | Why it matters | Best practice |
|---|---|---|
| Lift height | Pressure changes as the cylinder angle changes | Weigh at the same height on every lift |
| Lift speed | Fast lifts add a pressure spike | Lift smoothly at a steady, moderate speed |
| Oil temperature | Cold oil is thicker and reads differently | Warm the machine up before the first weighed load |
| Machine level | Tilt shifts the load on the cylinder | Weigh on level ground |
| Tare (empty attachment) | The bucket or forks have weight too | Zero with the empty attachment at the weighing height |
| Calibration | Every machine is a little different | Calibrate on the machine after install and on a regular schedule |
How to get repeatable weights, step by step
- Start the machine and let the hydraulic oil warm up.
- Park on level ground with the empty bucket or forks.
- Raise the empty attachment to your weighing height and zero (tare) the indicator.
- Pick up the load and lift it smoothly through the same height at the same speed.
- Read or print the weight once the display is steady, then add it to the total if you are loading to a target.
- Re-zero every so often during the shift, and whenever you change attachments.
If the display shows an error code instead of a weight, our guide to scale error codes explains the common ones. Printer models print a ticket per load; systems with a data output can also send weights to a computer (see how to connect a scale to a computer).
Installation and on-site calibration
MNM Scales technicians install Tara MNM Scales systems on your machine and calibrate them on-site. The installation covers fitting the pressure sensor into the lift circuit, routing and securing the cable, mounting the indicator and printer in the cab, and setting up the units and totals. Calibration is then done on the machine with known weights, so the reading reflects your machine, attachment and hydraulics.
- On-site service: $295 plus $2 per mile, round trip, charged once per visit. Calibration is priced per scale on top. See on-site scale calibration and industrial scale calibration.
- Shipped systems: every Tara system we ship is calibrated before it leaves our shop. After it is installed on your machine, a calibration on the machine gives the best accuracy.
- Quotes: installation and on-site calibration are quoted per machine. Call with the machine make, model and location.
- Technicians: MNM Scales has TDA-registered technicians for the scales that need them.
Loader scale vs floor scale
An on-board scale and a floor scale do different jobs, and many sites use both. The on-board scale weighs while the machine works; the floor scale is the fixed reference for pallets, drums and totes. For goods sold by weight, use an NTEP-approved scale (see what NTEP and legal for trade mean).
| On-board loader or forklift scale | Floor scale | |
|---|---|---|
| Where you weigh | On the machine, during the lift | At the scale location |
| Speed | Weigh as you load, no extra trips | Each load is driven to the scale |
| Best for | Loading to a target, tracking totals, checking loads | Pallets, drums and totes; sale-by-weight with an NTEP model |
| Calibration | On the machine | With test weights on the deck |
| MNM Scales options | Tara MNM Scales systems | NTEP stainless steel floor scales |
Choosing a floor scale too? See our floor scale buying guide. Need a scale for a short project? We rent all types of scales: see scale rentals.
Keeping a loader scale accurate
The problems our technicians see most often on weighing equipment of every kind are settings changed by mistake, including someone entering calibration mode by accident, and cables that get cut or crushed. On a machine, the sensor cable runs where it can be pinched by the boom or mast, so routing and securing it matters. A short checklist:
- Check the sensor cable and connectors for cuts, pinches and loose fittings.
- Keep the hydraulic fittings at the sensor tight and dry.
- Lock or password-protect calibration settings where the indicator allows it, and leave calibration to a technician.
- Check the weight against a known load regularly, and recalibrate on a set schedule (see how often a scale should be calibrated).
- If readings drift or jump, call us; repairs are done in our shop or on-site (see scale repair).
Why buy from MNM Scales
- Tara MNM Scales systems calibrated before shipping, with installation and calibration on your machine by our technicians
- One of the largest scale distributors and an authorized dealer for the brands we sell, in business since 1992 (over 30 years)
- In-house calibration with a certificate, or NIST calibration with a NIST-traceable certificate; mail-in calibration also covers scales bought elsewhere and is usually done within 1–3 business days after we receive the scale
- TDA-registered technicians; on-site service in the Houston area is $295 plus $2 per mile, round trip, charged once per visit, with calibration priced per scale
- Scale rentals of all types of scales
- Order pickup at our shop, 21249 FM 529 Rd, Cypress, TX, by appointment
- Phone answered 24/7 at (832) 290-3120
Ready to weigh on the machine? Send us the machine make, model, lift capacity and location, and we will recommend a Tara MNM Scales system and quote the installation and calibration.
Tara MNM Scales systems Call (832) 290-3120 Request an installation quote
Frequently asked questions
How does a loader scale work?
A pressure sensor in the hydraulic lift circuit measures the pressure as the load is lifted, and an indicator in the cab converts that pressure into weight. The system is calibrated on the machine with known weights.
How accurate is a forklift or loader scale?
A well-installed hydraulic on-board scale typically reads within about 1 to 2 percent of lift capacity when the operator weighs at the same height and speed, with warm oil, on level ground.
Can a Tara MNM Scales system be installed on my machine?
Tara MNM Scales systems fit front end loaders, forklifts, backhoes and other machines with a hydraulic lift. Call with the machine make, model and lift capacity and we will confirm the right kit and fittings.
Do you install and calibrate loader scales on-site?
Yes. MNM Scales technicians install and calibrate Tara MNM Scales systems on-site. On-site service is $295 plus $2 per mile, round trip, charged once per visit, and calibration is priced per scale.
Is the system calibrated before it ships?
Yes. Every Tara MNM Scales system is calibrated before it leaves our shop. A calibration on your machine after installation gives the best accuracy.
Is installation included in the price?
Installation, extra hydraulic fittings and on-site calibration are not included unless the listing says so. They are quoted per machine.
Can a loader scale print tickets?
Yes. Printer models include a thermal printer that prints a ticket for each load or a total for the shift.
Should I use a loader scale or a floor scale?
Use an on-board scale to weigh while loading and to track totals without extra trips. Use a floor scale for pallets, drums and totes, and an NTEP-approved scale for goods sold by weight.