Scales
We offer different varieties of scales: industrial scales, laboratory scales, precision scales, tabletop scales and many more. All these scales posses the characteristics and performance necessary to make measurements quickly and safely, and are guaranteed for 2 or 3 years, depending on the model of scales. Many scales can transfer data to a computer, have piece count functions and hopper functions. The scales come calibrated and can also come with a DIN ISO certificate. Also, if you require, calibratable models can be adjusted. Call us if you don't find the scales you are looking for to perform jobs effectively: +44 ( 0 ) 191 377 3398 or request a copy of our catalogue of scales (printable version) in which you can browse our vast selection of scales at your leisure and compare the various models.

Below is a division of our scales into a general index with links for corresponding products. Then you will be able to see some images of the groups of scales which will help clarify the types of instruments you might be looking for. If you click on those links, you will find the specific product pages for our scales. If you wish to obtain more information about our scales for your company, you can request our catalogue by simply clicking here. Other information regarding scales can be found at "other information and links".

General index

Our scales, depending on the model, meet with all technical requirements and weighing standards within all industries. As part of our scales, we have optional accessories available. The images below illustrate some example of these accessories.
                                                                                
                           Software kit                                   Printer                                        Density                                     Calibration

A legal verification of scales (only for verifiable models) can be done by us (class II and class III) or by an authorised verification centre for class II. Once an authorised verification has been performed, the scales cannot be calibrated using an external calibration weight. An authorised verification is valid for 2 years, at which point a verification must be done annually. For companies that have an internal control or external audits, it's acceptable to perform an annual ISO calibration. The ISO certification comes with an additional document containing the test values. The certification can also include the company's address and details.

Images of the groups of scales

Analytical scales

Pocket scales

Scales can determine weight as well as other things 
Scales are used to determine the weight of a particular body or the magnitudes related to weight, such as volume or density. The determination of weight is very important in many sectors, especially within production and the commercial sector.
Scales are used for all kinds of jobs within industry, the commercial sector, transport, research and development, education and privately. Here are some examples:

Alphabetical information and links about scales
Together with our range of scales and the professional assessment made by our engineers and technicians, we also provide you with an alphabetical list of relavent terminologies to help our customers to properly inform themselves before acquiring one of our scales.



Adjust: establishing an exact magnitude of measurement in a device, such as for scales, by way of technically intervening with the measurement system.

Adjust the weight range: this can be done using a control weight and the adjustment setting (CAL), or also with an internal automatic adjustment connection. This is required due to changes in temperature, changes in ambient conditions, location change, etc. This adjustment should be done routinely throughout the day.

Authorisation of adjustments to scales: calibrations of scales is dicumented once the device has been authorised. The device must first be submitted to a technical calibration test which is done by an official organisation, usually an state meteorological institution. The technical requirements of the measurement and the specifics of the device are taken into consideration.
This authorisation is documented with an EU certification (IEC Type approval certificate).
This EU authorisation is valid across all member states of the EU.

Authorisation of scales: this is carried out be the PTB Federal Office. Scales can only be adjusted if there is authorisation for this format.

Terrestrial forces: have an destablising influence on electronic scales. The scales should be adjusted in an enclosure as the device's energy will be different at different points of the earth.

High resolution scales: under this denomination are analysis scales and precision scales with a resolution of >100,000 digits. The resolution is calculated from the weight range: reading capacity d
Example: weight range of 300g, at a reading capacity of 0.001g corresponds to 1mg, the resolution = 300,000 digits.
Scales - Classifications of accuracy

Calibrated / non-calibrated scales: with respect to technical measurements, they are almost identical. In the case of scales which can be calibrated, some prescribed specifications exsist, such as software modifications or additional labels.

Commercial scales: class III scales. These typically include shop scales.

Industrial scales: this covers a wide range of scales, covering tabletop scales, platform, scales, crane scales as well as scales used for shipping and receiving.

Laboratory scales: under this classification you will find analytical scales and precision scales.

Micro scales: Analytical scales which can take a minimum load of between 5g and 50g, with a reading capacity d = 0.001mg or higher.

Semi-micro scales: analytical scales with a reading capacity d = 0.01mg.

Scales with 'stand by': they partially shut down if not being used. This eliminates the start up time when tey need to be re-used, which saves time.

Scales with various ranges: scales with a variety of different weight ranges. Each weight range begins at zero and stops at the maximum load for the scales. Each weight range has its own reading capacity "d".

Calibration: According to EU directives 90 / 384 / EWG, all scales should be officially calibrated if they are going to be used for:
a) In commercial ventures where the cost of a product is determined by its weight.
b) The manufacture of medicines in pharmacies, such as in the analysis in medical laboratories or pharmaceuticals.
c) For determing fees, tariffs or official fines. Also for technical expertise in court cases.
d) The manufacture of packaging.
All scales are tested in an authorised calibration centre and are identified with a calibration mark. This marking corroborates its accuracy within the tolerance frame of calibration. The scope of EU calibrations extend across all the member countries of the EU.

Calibration of scales with an automatic adjustment or with an automatic connection. All the previously mentioned references lose validity, which can be managed by an automatic adjustment after a calibration. In this case the calibration is done independantly of a enclosure.

Calibrate: to establish a correction of the magnitude of a measurement in a device without intervening in the system of measurement. Example: testng of scales with a test weight. The term 'calibrate' was previously employed to mean 'adjustment'. Laboratories for calibrating scales.

Reading capacity d: the smallest legible value on scales.

Minimum load (min): lowet limit of an adjustable measurement range. It can be found indicated on the adjustment plate. Scales can also function below the minimum load.

Start up time: the amount of time from when the scales are turned on until it has reached its operating temperature.
This is almost always indicated in the user's manual. also see >> Changes in temperature.

Calibration certificate: document containing the technical characteristics of scales or test weights, which are traceable to a National standard. Calibration certificate for scales

Certification according to DIN EN ISO 9001: the certification shows that a company meets with all the required quality management system according to DIN EN ISO 9001 standards. After speaking with the appropriate authorities, a certificate can be obtained according to the quality mangement system standard DIN EN ISO 9001.

Compensation for electromagnetic energy: electronic analysis scales and precision scales of higher wuality operate according to this measurement principle. The base consitutes the physical effect of the effect of energy that an electrical coil experiences within current in a permanent magnetic field.

Piece counting: if you weigh, for example, 10 equal pieces, the reference number of pieces is 10. Scales automatically determinethe average weight by the quantity of pieces. From this moment, the identical components to count are referred to as pieces. A larger number of reference pieces result in a more accurate calculation.

Control of the testing method: performance of  quality management systems according to ISO 9000 and others such as the GLP. They have to test the correction of the method of measurement (scales) and the methods of control (weights) at defined intervals, which is to say that they require calibration. This test should include documantation.

Load control at scales edges: control of the scales when a load is placed near the edge of the weighing pan.

Declaration of conformity: the declaration of conformity documents that a product corresponds with EU directives. In terms of electronic scales, they come with the CE certification mark.
Declaration of conformity for scales

Determination of percentage: for example, the reference weight af a sample before drying it is 50g = display of the scale at 100%. After drying, the sample is 40g = display of the scales at 80% absolute (dry mass) or 20% relative (humidity).

DKD: German calibration service.
An authorised DKD laboratory for issuing calibration certificates.

Division: in digital scales, this is also called >> Reading capacity d. In non-mechanical scales, the minimum value is indicated in a scales composed of lines and figures that are read by way of an index or indicator.

Document of conformity: when sclaes are calibrated a document of conformity is drawn up by the authority carrying out the adjustments.

Duration of the validity of a calibration of scales: analytical scales of calibration class I, 2 years; precision scales of calibration class II, 2 years; industrial scales of calibration class III, 2 years; all other classes, 1 year.

Duration of the validity of a calibration of weights: weights in error limit class E2, 4 years; weights in error limit class F1 - F2, 4 years; weights in error limit class M1 - M3, 4 years, weights in all other classes, 1 year.

EA: European co-operation for Accreditation (previously WECC or EAL). Regulates the mutual international recognition of DKD certificates for scales. Link for the EA.

Effects of air: each body experiences a push of air, loss of weight, that does not disappear when using highlt accurate weights. To neutralise this, in practice, a conventional weight value is introduced. The effects of air should be taken into consideration when weighing an object.

Filter to adapt to ambient conditions: they filter the sudden movements increasing the number of internal measurement cycles in the scales or increase the time of integration. It is additional security above the control status that is eliminated in a measurement value being read or printed too quickly. Different levels of filters can be adjusted. See also weighted value.

Margin of error for scales: the uncertainty in measurements characterises the range in which you will find the real measurement range.

Capacity indicator: a luminous band ascending on the display indicates the occupied weight range and the available range. It eliminates the risk of intentionally going out of range.

Indication of an overload: shown on the display of scales when a minimum or maximum load is exceded.

Influence of temperature on scales: these are physical conditions and can only be corrected with internal device compensation. It is necessary to adjust scales after a change in temperature. >> Adjust.

Interface parameters: almost always RS-232 C. to connect directly to a computer or printer.

ISO 9000 and higher: quality management system within the quality assurance standard for companies known as DIN EN ISO 9000 and above.
 
        

Error limit for scales: refers to adjusted scales. the error limit refers to the permitted tolerance or, that is to say the allowed deviation of weight. There exists a difference between error limits  from the first adjustment and error limits used by the scales.

Error limits for weights / classes of error limit: a weight's error limit corresponds with the permitted tolerance, which is to say the largest allowed deviation from the nominal value. Error limit classes for weights are established by OIML in a strict hierarchical manner.

Error limits when used: they are the double of error limits for scales for their first adjustment. They are the permitted error limits for scales in use.

Characterictic line of scales: graphical representation of the weight indication in scales with weight control from zero up to a maximum load.

Linearity / Correction of scales: maximum deviation of the weight display with respect to the test weight value across the entire range.

Weighing table: analysis scales and precison scales should exclude all sudden movements. The solid stone plates should rest upon wall mounted consoles or stable tables. Their horisontal position should not need to be modified.

Metrology: measurement discipline of measurement units and systems. In the case of scales, it is directly related with the calibration technique. see also >> OIML 

Number of reference pieces: number of pieces needed to obtain a represetative weight reference for piece counting. Almost always between 5 and 50 pieces.

Total net: the possibility to put the weight in seperate memory locations for making recipes. The net total is the sum of weights of all the components, excluding the weight of the receptical and can be calculated at the press of a button.

Newton: the Newton (N) is a unit of force in the System International (SI).
A body accelerates at a force of 1 kg for 1m/seg².

OIML: Organisation Internationale de Métrologie Légale. This organisation regulates the metrics of legal calibrations (Meterology). A link for the OIML

LCD (Liquid Crystal Display): term used to identify a type of display which incorporates liquid crystal and is not illuminated on its own.

LED display (Light Emitting Diode): It uses the light emitted from light diodes to display values or indicators.

Weight differential: determination of the difference in weight of an object after a process, wuch as drying. Both weights are taken on the same scale under the same conditions.

Weight range tolerance: The upper and lower value limits are individually programmed into the scales either with weights or by using the keypad. To classify a luminous bar oscillates between value limits and an acoutic signal is emitted. Limit values are done in grams (g) per piece or percentage (%).

Heavier / lighter weght: for tesing quality: load the scales wth a nominal weight - reset the tare to zero by presing the TARE key, which saves the nominal value - all measurements taken will be shown in relation to the nominal weight.

Weight: the weight of a body is a physical magnitude. It is measured by the effect of the inertia of a chnage in velocity, such as an attraction to other bodies. Weight is always the same, independant of the effects of air and the attraction to the earth. The metric unit is the kilogram.

Absolute density: determination of the weight of an object in units of milligrams (mg), grams (g), kilograms (kg) or tons (t).

Gross weight: weight of an object including packaging and or the transport container >> Net weight, >> Tare.

Net weight: weight of an object excluding packaging and or the transport container >> Gross weight, >> Tare.

Tare weight: weight of the container or packaging of an object. see also >> Gross weight, >> Net weight.

Test weights: weights that correspond with a measurement class of error limit M1 of the OIML . Used for testing precison scales and industrial scales..

External test weight: (calibration weight), used to adjust or calibrate precision scales >> Adjust weight range. An external test weight can come with a DKD certificate.

Internal test weight: like the external test weight, but is incorporated within the scales and functions using a motor.

Reference weight: the representative weight when for piece counting equal components >> Number of reference pieces.

Commercial weights: weights of OIML within error limit class M3.

Pasteur tube: manual device that offers the possibility to measure the weight of small quantities of liquid.

Wind screen: aparatus that protects the weighing pan against disruptive movements produced by air flow. It's required by precision scales wth a reading capacity d <10mg. It comes with all analytical scales.

ISO / GLP protocol: in quality assurance systems, its necessary to print weighting results, first values, and the the weight correction adjustment with the date and time, as well as the scales identifier. The easiest way is by connecting a printer.

Prototype of the International kilogram: también se denomina "kilogramo originario" y es la unidad base de la masa. Esta pieza de 1 kilogramo se conserva en París. Es la referencia mundial para el sistema métrico. De él derivan el gramo (g), el miligramo (mg) y la tonelada (t)

PTB: Physikalisch Technische Bundesanstalt in Braunschweig. This Federal Offices responsible for the legal Metrology OIML in Germany. In the case of scales, they regulate calibrations.

Metric carat: a metric carat is 1ct = 0.2g. It's used for determining the weight of precious stones.

Maximum weight range: operating range for scales. Scales can be loaded up to the maximum load limit.

Temperature range: the range in which scales can be used. If the scales are used in temperatures too high or low, errors can be produced.

Mixing components: weighing different components in a receptical allowing for them to be mixed, for making recipes. >> Total net

Re-adjust: periodical testing and adjustment of scales by an authorised centre. see also >> Duration of validity of calibration of scales

Recalibration: periodical measurement of the method of measurement or or control, to test its correction.

Recovery of the national norm: the ISO 9000 standard ensures that all measurements meet the defined tolerance of the official standard. see also >> International prototype kilogram

Repeatability: (standard deviation) the coincidence of repeated measurements under the same conditions. Almost always 1d or less. Qualitative characteristic

Tare: the possibility to reset the display to zero once a receptical is placed on the weighing pan. This can be done as often as required with electronic scales. The tare is subtracted from the device's maximum weight range. For example: the maximum weight range is 6000g, the tare (= a receptical) 470 g, maximum available weight range = 5530g.

Ingress protection (IP): the higher the number, the better protection against dust and water that the scale's enclosure has.  IP 54 is standard for scales. Table of the types of Ingress Protection

Tolerance of a measuring device: each device has an indicated tolerance to physical conditions. Tolerance defines the most deviation allowed. see also >> Error limit

Validation: document demonstrating that a process is more appropriate for performing a tare.

Calibration value e: measured by the calibration tolerance according to the type of scales, between 1 and 10d.

Weight value: indicated by the scales after weighing. This is usually shown in either (g) or (kg). Results can be simply read or printed.

Conventional value of a weight: effect of a weight on scales under ideal circumstances: material density 8000kg/m³, relative temperature 20°C, density of air during the measurement 1.2kg/m³. 
The conventional value of a weight is facilitated by precision weights, and the present oscillations due to the density of air up to ±10% do not have to be taken into consideration.

Verification: document demonstrating that the device has met with and established requirement.

The ABCs of scales has been devised by our associates Kern & Sohn GmbH.

Other sources: Scales in the PTB

Data protection

Request a copy of our catalogue for scales (company copy).

Below we have a video of our company where you can observe where research, innovation and technical assistance are the most important services which we provide to our clients. If none of our scales are a solution to your problem, call us on: +44 ( 0 ) 191 377 3398 and one of our engineers will assess your needs and help you select the scales which best suite your situation.