Balances
We offer different varieties of balances: industrial balances,
laboratory balances, precision balances,
tabletop balances and many more. All these balances
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 balances. Many balances can
transfer data to a computer, have piece count functions and
hopper functions. The balances 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 balances you are looking for to
perform jobs effectively: our offices:
+44 ( 0 ) 191 377 3398
or request a copy of our
catalogue of balances
(printable version) in which you can browse our vast selection of
balances at your leisure and compare the various models.
Below is a division of our
balances into a
general index with links
for corresponding products. Then you will be able to see
some images of the groups of balances 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 balances. If you wish to obtain more information
about our balances for your company, you can request our
catalogue by simply clicking
here. Other information regarding balances can be found at "other
information and links".
Our balances, depending on the model, meet with all
technical requirements and weighing standards within
all industries. As part of our balances, we have
optional accessories available. The images below
illustrate some example of these accessories.
Software kit Printer
Density
Calibration
A legal verification
of balances (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 balances 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.
balances can determine weight as well as other things
balances 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.
balances 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 balances
Together with our range of balances 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 balances.
Adjust:
establishing an exact magnitude of measurement in a device,
such as for balances, 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 balances:
calibrations of balances 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 balances: this
is carried out be the PTB Federal Office. balances can only be
adjusted if there is authorisation for this format.
Terrestrial forces: have an
destablising influence on electronic balances. The balances
should be adjusted in an enclosure as the device's energy
will be different at different points of the earth.
High resolution balances: under
this denomination are analysis balances and precision balances
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.
balances - Classifications of accuracy
Calibrated / non-calibrated balances:
with respect to technical measurements, they are almost
identical. In the case of balances which can be calibrated,
some prescribed specifications exsist, such as software
modifications or additional labels.
Commercial balances: class III
balances. These typically include shop balances.
Industrial balances: this covers
a wide range of balances, covering tabletop balances, platform,
balances, crane balances as well as balances used for shipping and
receiving.
Laboratory balances: under
this classification you will find analytical balances and
precision balances.
Micro balances:
Analytical balances which can take a minimum load of between
5g and 50g, with a reading capacity d = 0.001mg or higher.
Semi-micro balances: analytical
balances with a reading capacity d = 0.01mg.
balances 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.
balances with various
ranges: balances with a variety of different weight
ranges. Each weight range begins at zero and stops at the
maximum load for the balances. Each weight range has its own
reading capacity "d".
Calibration:
According to EU directives 90 / 384 / EWG, all balances 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
balances 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 balances
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 balances with a test
weight. The term 'calibrate' was previously employed to mean
'adjustment'.
Laboratories for calibrating balances.
Reading capacity d: the
smallest legible value on balances.
Minimum load (min): lowet limit
of an adjustable measurement range. It can be found
indicated on the adjustment plate. balances can also function
below the minimum load.
Start
up time: the amount of time from when the balances 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 balances or test weights, which
are traceable to a National standard.
Calibration certificate for balances
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 balances
and precision balances of higher quality 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. balances 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 (balances) 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 balances edges:
control of the balances 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
balances, they come with the CE certification mark.
Declaration of conformity for balances
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 balances at 80% absolute (dry
mass) or 20% relative (humidity).
DKD: German calibration
service. An authorised DKD laboratory for issuing
calibration certificates.
Division: in digital balances, this is also called >>
Reading capacity d. In non-mechanical balances, the minimum
value is indicated in a balances 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 balances:
analytical balances of calibration class I, 2 years; precision
balances of calibration class II, 2 years; industrial balances
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 balances.
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
balances 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 balances: 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 balances when a minimum or maximum
load is exceded.
Influence of
temperature on balances: these are physical conditions
and can only be corrected with internal device compensation.
It is necessary to adjust balances 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 balances: refers
to adjusted balances. 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
balances.
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 balances for their
first adjustment. They are the permitted error limits for
balances in use.
Characterictic line of balances:
graphical representation of the weight indication in balances
with weight control from zero up to a maximum load.
Linearity / Correction of balances: maximum deviation
of the weight display with respect to the test weight value
across the entire range.
Weighing table: analysis balances
and precison balances 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 balances, 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 balances 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 balances
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 balances and industrial balances..
External test weight:
(calibration weight), used to adjust or calibrate precision
balances >> 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
balances 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 balances wth
a reading capacity d <10mg. It comes with all analytical
balances.
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 balances 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 balances, 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 balances. balances can be loaded up to the
maximum load limit.
Temperature range: the range in
which balances can be used. If the balances 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
balances by an authorised centre. see also >> Duration of
validity of calibration of balances
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 balances. 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 balances.
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 balances, between 1 and 10d.
Weight value: indicated by the
balances 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
balances 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 balances has been devised by our associates Kern &
Sohn GmbH.
Other sources:
balances in the
PTB
Data protection
Request a copy of our
catalogue for balances
(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 balances 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 balances
which best suite your situation.
PCE Group has
tested some of our measuring instruments in the Antarctic. Our
aim was to ensure that our measuring instruments could resist
extremely low temperatures. In a recent expedition, we exposed some
of our pocket and laboaratory balances to these conditions. Such
extreme tests ensure that our devices will function inside freezer
units for prolonged periods of time.