Scales & Balances Calibration

Scales & Balances Calibration

Accurate & Reliable

To maintain the accuracy and dependability of your devices, we employ Class F1 calibration weights as classified by the International Organisation of Legal Metrology (OMIL).

Available on-site or in a laboratory

Covering the majority of balance and force device makes and models, you can select between on-site calibration at your location or our laboratory service.

Why choose us?

Whether your scales are calibrated in our laboratory or on-site, we can guarantee that they are accurate.

Since we are aware that imprecise scales may result in lost sales or negatively impact the quality of our products, we have invested heavily in Class F1 Calibration Weights, as defined by the International Organisation of Legal Metrology (OMIL).

*We can calibrate scales for pallet trucks weighing up to 1.5 tonnes. For scales larger than this cutoff, please give us a call.

Our group of exceptionally skilled experts can calibrate a large range of scales. If it is more convenient for you, we can provide on-site calibrations at your location. We are able to carry out calibrations using our ISO9001 calibration lab on-site.

In addition, we have the ability to repair test equipment if necessary. During a calibration, the team may occasionally discover mistakes. If you approve, we can fix these issues, calibrate your device, and guarantee that your test equipment is safe to use and produces accurate readings for an additional year.

Types of Scales & Balances

We offer calibration on the following scales and balances:

Precision Balances

Lab Balances

Laboratory Balances

Lab Scales

Laboratory Scales

Analytical Balances

Sartorius Scales

Sartorius Balances

Electronic Weighing Scales

Salter Scales

Industrial Scales

Weighing Scales

Weighing Balances

Analytical/Lab

Baby Scales

Bariatric Scales

Bathroom Scales

Calibration Weights

Cannabis Scales

Checkweighing Scales

Counting Scales

Crane Scales

Education Scales

Explosion Proof

Farmers Market

Fishing/Game

Food/Deli Scales

Floor Scales

Force Gauges

Height Measurement

High Capacity Precision

Industrial Scales

Jewelry Scales

Kitchen Scales

Laundromat Scales

Legal for Trade

Legal for Trade

Medical Scales

Medicinal Cannabis

Moisture Analyzers

Pallet Jack Scales

Physician Scales

Retail Scales

Recycling Scales

Specialty Medical

Shipping Scales

Test Stands

Veterinary Scales

Wheelchair Scales

Wheel Weighing Scales

Manufacturers

Acculab

Adam Equipment

American Weigh

AND Weighing

Avery Berkel

Avery Weigh-Tronix

Aczet

Best Weight

Cambridge

CAS

CCi

Chatillon/Ametek

Cubetape

Detecto

DIGI

DigiWeigh

Dillon

Doran Scales

Easy Weigh

Fairbanks Scales

Gram Precision

HealthOMeter

Hoto Instruments

Imada

Inscale

Intelligent Weighing

Intercomp

Ishida

Mark 10

MedWeigh

Mettler Toledo©

Minx

Minebea Intec

MSI

NCI

Ohaus

Pennsylvania Scale

Pesola

Precisa

RADWAG Balances

Rice Lake Scales

Rice Lake Cal Weights

Salter Brecknell

Sartorius

Seca

Setra

Shimpo

T-Scale

Tanita

Torrey

TREE

Troemner

US Balance

UWE Scales

Vibra

WeighMax

WeighSouth

Other Products

Airport Baggage Scales

Coffee Scales

Body Fat Monitors

Mass Comparators

Pro Body Composition

Types of Weighing Scales

Almost everywhere is where scales are used. Weight measurements are the foundation of everyday consumer transactions. To ensure we pay the right amount of money when purchasing an apple quantity, we must be certain of the apples' exact weight. Building, food, pharmaceutical, and medical industries are among the industries that use weighing scales. Weighing scale calibration is necessary for a variety of reasons, including health, safety, invoicing, and more. If our scale is measuring correctly, we need to know. Every few months or even weeks, commercial scales may require calibration.Scales may lose their accuracy for a variety of reasons. Occasionally, wear and tear on their mechanical or electronic components may result in a shift in the reading. Environmental influences also have a significant impact. A scale that is designed to function precisely in a cold setting, such as a refrigerator, will not function the same way in a warm, muggy setting like a bakery.

What separates automatic scales from non-automated scales

Weighing devices that are automatic are those that can carry out successive cycles of weighing without the need for operator assistance. Measuring Instruments Directive regulations apply to this particular category of instruments.

Weighing machines that need an operator to ascertain or confirm the weight reading are classified as non-automatic. Any clever operator action that influences the outcome, such as determining when an indication is stable or modifying the weight of the weighed product, is included in determining the weighing result. Making a decision about whether to accept each weighing result based on the indication is known as verifying the weighing result.

The following terms and procedures relate to weighing devices that are not automatic.

The SI measurement unit of weight is the kilogram (kg). Kilogram, milligram (mg), gram (g) and tone (t) are the most common units used by scales.

A scale may be equipped with:

·        Load-measuring device

·        Display

·        Printer

·        Preset tare function

Weighing scales are classified according to:

·        the verification scale interval (e), representing absolute accuracy and

·        the number of verification scale intervals (n), representing relative accuracy

A minimum capacity (Min) is also specified to indicate that any use of the instrument below this value is likely going to produce considerable relative errors.

Non-automatic weighing instruments are characterized by their accuracy class which is defined in OIML R76-1, as shown in the following table:

OIML R76-1 also provides the following table for the classification of weighing scales according to their verification scale interval (e), number of verification scale intervals (n) and the minimum capacity (Min), in relation to the accuracy class:

Maximum permissible errors for initial verification and for re-calibration are also defined in OIML-R76-1.

About Scale Calibration

Calibration of Non-Automatic Scales

After explaining the basic functions and metrology requirements of non-automatic weighing instruments, we can now discuss their calibration.

Calibration consists of: • the measurements performed; • the calculation of the measuring results; • the determination of measurement uncertainty; and • the issuance of a calibration certificate.

The object of calibration when calibrating a scale is the indication provided by the instrument when a load is applied. Local gravity, the load temperature and density, and the temperature and density of the surrounding air all influence the load value indicated by the scale.

When calibrating a weighing scale, we do the following:

1. Place test loads on the scale under the specified conditions.

2. Determine the indication's error or variation, and

3. Assess the measurement uncertainty associated with the results.

Calibration Range

In most cases, the calibration must cover the entire weighing range. (from the smallest (Min) to the largest (Max) capacity). The customer may, of course, specify the desired calibration range or individual calibration values. The best method would be to perform the calibration on the site where the instrument is used. There are many effects that can alter the performance of an instrument in the case when it is moved to another location and might invalidate the calibration. Some of these effects are:

·        variation of the environmental conditions

·        difference in local gravity acceleration

·        mechanical and thermal conditions during transportation

Before proceeding with the calibration, the weighing scale must be checked to ensure that it functions properly and that the indications are easily readable. According to the manufacturer's instructions, the scale must be energised before calibration for an appropriate period of time. The instrument must be levelled if applicable. Any special manufacturer instructions describing how to use the scale must be followed.

Calibration Methodology

The calibration measurements determine the following:

• Indication repeatability • Indication errors • The effect of eccentric load application on the indication

Repeatability Test

The test is performed by depositing repeatedly the same load on the weighing scale, under identical conditions (of both the load and the instrument). There is no need for the test load to be calibrated or verified.

For the repeatability test, a test load L_T must be selected which, for weighing instruments with a constant scale, usually has the following relationship with the Max:

0,5Max £ L_T £ Max

Before testing repeatability, the indication of the weighing scale must be set to zero. Then the load is applied at least 5 times (or at least 3 times when L_T ³ 100 kg).

Every indication corresponding to each deposition of the load is recorded. It is important to check, after each removal of the load, if the indication returns to zero. If this does not happen it must be reset to zero.

Example: On a scale with 200g capacity and scale interval of 0,1mg, we perform repeatability test with a 100g load and record the following indications:

100,0002g

99,9999g

100,0001g

100,0000g

100,0002g

100,0002g

The repeatability error is determined by the standard deviation s according to the following formula:

where n = 6 (the number of repeats)

and plying the formu to our results, we have a repeatability error: s = 0.13 mg.

Test for errors of indications

The purpose of this test is the evaluation of the scale’s performance over the complete weighing range. The standard loads used for this test must be properly calibrated with an established traceability and measurement uncertainty.

This test is performed with at least 5 different test loads, fairly distributed over the instruments weighing scale. For example, 5 test loads can be zero or Min, 0,25Max, 0,5Max, 0,75Max and Max. Other test points can be used upon customer’s special requests.

Prior to the test, the indication must be set to zero. The method of calibration can be one of the following:

·        Increasing load by steps with unloading between separate steps (this is the procedure corresponding to the majority of cases

·        Continuously increasing loads by steps, without unloading between separate steps, but adding a new load

·        Continuously increasing and decreasing by steps

·        Continuously decreasing by steps, starting from Max

The indication for each load is recorded. After each removal of the load, the indication must be checked for returning to zero and if not, to reset it to zero.

Example: On the same scale as above, with 200g capacity and scale interval of 0,1mg, we perform calibration by applying the following loads and having the following results:

Eccentricity Test

This test is carried out by positioning a test load on the weighing scale in such a way that the load's centre of gravity takes the positions indicated in the figures below or equivalent positions as precisely as possible.

1.     Centre

2.     Front Left

3.     Back Left

4.     Back Right

5.     Front Right

The test load used for the eccentricity test does not need to be calibrated. The value of the test load should be at least Max/3 unless otherwise specified by the manufacturer.

Before starting the test, the indication must be set to zero. The load is first put on position 1 and then moved to the other four positions in arbitrary order. At last, it is put again on position 1.

Each time, indications must be recorded and after each removal of the load, we must make sure that the indication returns to zero.

Example: To our weighing scale, with 200g capacity and scale interval of 0,1mg, we perform eccentricity test by applying to the five positions a 100g load. The results of the measurements are as follows:

In order to calculate the eccentricity error, we calculate the difference between each position reading with the position 1 reading:

The eccentricity error presented in the calibration certificate is the absolute value of the higher difference. In our case:

Scales must be regularly calibrated in order to provide accurate results.