Calibration service

Quick overview

- Certificates traceables to internacional masters and therefore suitable to fulfill the ISO 9000 quality standards.
- These are not official certificates. In that case you should refer to National Accredited Laboratories.
- Price for standard certificate: 22€. Express service 24 h: 28€. (calculation of the uncertainty upon request: 36€).
- Estimated delivery time: 1 week.
- We also extend test certificates of our costumers´ manometers (not supplied by us).
- We include copy of the primary master used in the test.

Calibration of instruments

According to the International Vocabulary of main and general terms of Metrology (VIM), the calibration is a ensemble of operations aimed to settle, in certain pre-set conditions (see Calibration Procedures), the correspondence between the values indicated by an instrument and those values known refered to a master, ensuring thus the traceability of the lectures given by the instrument to the basic units of the International System (SI), adjusting the instrument if necessary and expressing this correspondence by means of a table or a graphic.

Abad Controls, s.l., certified company according the ISO 9001:2000 Norms, issues calibration tests for pressure instruments with accuracies 0.6, 1.0, 1.6 and 2.5 with demonstrable traceability (upon request up to the primary national or international master). Anyhow, notice that our test certificates are not official tests; in that case we refer to any of the national laboratoires authorized for that purpose.

Reasons to calibrate

The aging of the components, changes of temperature and the mechanic stress suffered by the instruments slowly deteriorates their functions. When this takes place, the measures began to lose reliability and therefore the performance as well as the quality of the product decreases. This depletion can be detected and limited through the calibration process.

A proper calibration of the instruments provides the certainty that our instruments gather the required specifications. Therefore the point of these confirmations is:

- Maintain and verify the correct performance of the equipment.
- Give response to the required quality standards, (e.g.: requirements related to the ISO9000 Norms).
- Assure the reliability and traceability of the measures.

The calibration of an instrument allows to know its uncertainty, an essencial value within a quality system to group the instruments in metrologic categories for its further use.

Traceability

Is the property of an instrument that allows to refer it to proper measure masters, usually national or international masters, by means of an unbroken chain of comparisons. According to the ISO 9000 Norms, all the masters used in instrument calibration should be traceable higher rank masters (also called primary masters) belonging to an authorized laboratory, it is, tested in turn by an official organization with a master of better accuracy. Those primary masters should attend their own test certificate, where will clearly appear the source, the uncertainty, the calibration date and the environmental conditions when the results were obtained.

A unique calibration mark or TAG is documented for every instrument, that will also be reflected on the corresponding certificate. On the certificate it will be documented as well the type, serial number and uncertainty of the master used, calibration date, stated interval recalibration, calibration method, obtained calibration results, maximum error permitted, master traceability, environmental conditions and names of responsible) of calibration as well as the calibration department chief signature.

The masters used are at least four times better for class 0.25, and until forty times better for class 2,5.

Learn more at:  www.enac.es    www.european-accreditation.org

Duration ot the test certificates

It is not stated a standard interval of metrological calibration. It depends on the case of application and frequency of use, accuracy required, etc. AbCo recommends an annual recalibration of the pressure gauges.

Types of certificate

 AbCo Calibration Report

 Made according the internal Test Procedure Nº 837-1.
This certificate has two pages. On the first one it is detailed the characteristics of the instrument to be calibrated, as well as those of the master used and its traceability. In the second one are transcribed the readings rising (increasing value) and falling (decreasing value), reflecting the error % span on a calibration graphic.

AbCo Calibration and Uncertainty Report

In this case we apply the Calibration Procedure P-002 edited by the Industry and Energy Ministery of Spain.
That certificate is composed of three pages. On the first one are related the features of the instrument to be calibrated as well as the master and its traceability. On the second one are indicated the obtained results (3 cycles) upwards (increasing) and downwards (decreasing), and drafting from these results the medium value, correcting value, the histeresys and the errors % of span, reflected on a graphic. On the third page are indicated the typical deviations and uncertainties obtained, assigning to the instrument the largest one.

Calibration procedures

 CALIBRATION PROCEDURE Nº 837-1

• The instrument to be calibrated will be introduced inside the room where the calibration will take place, in order to make environmental conditions as similar as possible as those of the reference master. The test room is equipped to achieve the environmental conditions (temperature, humidity, etc) required.
• Both instruments (master and the one to be calibrated) are connected to the pressure or vacuum generator depending the range:

- Pneumatic pump for verification through compurgation. Fluid used dry and filtered air. For ranges from o up to 6 bar.
- Hydraulic pump for verification through comparison. Fluid used distillated water. For ranges from 6 to 400 bar.
- Hydraulic pump for verification through comparison. Oil operated pump, for ranges from 600 up to 1600 bar
- Vacuum pump, for ranges from 0 up to -1 bar.

•   Measure units (bar, kg/cm², psi…) are introduced on the master pressure transmitter used to make the verification.
•  In case of manometers, the oil filling nipple or blow out disc will be removed in order to equals the pressure inside the manometer and atmospheric pressure and avoid false pressure readings.
•  Pressure or vacuum will be generated, depending on each case, inside the calibration circuit, taking the instrument twice up to its final scale for awakening it, falling back to zero after the operation.
• The calibration itself will take place generating pressure (or vacuum) and noting five, six or more readings (equidistant) rising and falling (1 cycle), depending on accuracy and range, for instruments class 0,6 / 1,0 / 1,6 / 2,5.

Terms 

• Instrument:  Pressure or vacuum device to be calibrated.
• Accuracy (class): Positive or negative deviation of a value from another one accepted as reference master or ideal value.
• Master: Measuring instrument destined to define, realize, or reproduce one or more magnitudes values in order to be used as reference for other comparisons.
• Correction: Value that, algebraically added the not corrected result of a measuring allows to compensate a pretended systematic error respect a ideal value.
• C= Nominal master Instrument readings.
• Span: Difference between the upper an lower range.
• Error % span: Quotient between the differences of reading and span, all multiplied per 100.

            Instrument readings – Nominal Master

E  =    -------------------------------------------------------------    x   100

                                       Span

• Traceability: It is the property of a measuring instrument that allows to refer it to suitable masters, generally national or international, through a unstopped chain of comparisons. According to ISO 9000 norms, all masters used in the calibration processes must be traceable to upper masters (or primary masters) from accredited laboratories, it is, been calibrated in an official organism.. All primary masters will be accompanied of their calibration certificate, where source, calibration date, uncertainty and environmental conditions will be reflected.