Calibration Information From Denmark – The basic design of a temperature calibrator and Accredited Calibration Traceability
Image Caption: 1. The raw sensor output
2. After a transmitter (4-20 mA), 3. Manual reading on an indicator 4. The control data in the control room
Allerød Danmark — AMETEK Calibration Instruments, better known as JOFRA, publishes a wide range of calibration information for contact temperature sensors in their literature and on their website, www.ametekcalibration.com.
Here’s some text an an image from a story about the dryblock type of contact sensor temperature sensor calibrators.
“In order to maintain consistent quality of manufactured products, it is necessary to perform periodic calibrations on process sensors and instruments. There are several philosophies for calibration of measurement and control circuits.
“The basis of the chosen method should always be to include the temperature sensor.
“It does not make any sense only to calibrate and adjust the electronic part of the loop. A rule of thumb says that only 10% of the total error is in the electronics, the other 90% is due to the sensing element.”
A temperature sensor then is best tested when it is meaning physically exposed to the desired temperature. A dry-block calibrator is an easy method to simulate the ‘process’ temperature.
CALIBRATION CERTIFICATES
Accredited certificates
Laboratories under national calibration bodies can only issue accredited calibration certificates, and for Europe those bodies are again member of EA. EA is The European co-operation for Accreditation
All accredited certificate have the rights to use the national logo for accreditation on the front page of the certificate. For Denmark the organisation is called DANAK.
(NOTE: In the USA, Temperature Calibration Laboratories are accredited by both NAVLAP, organized by NIST and A2LA, an independent laboratory accreditation organization.
Around the world there are other accreditation systems and many are interlinked by Memoranda of Understanding -MOU.
Visit the website of any of these groups or that of the International Bureau of Weights & Measures, known popularly by the acronym for its name in French, BIPM to learn more. This learning can include the situation within your country and an opportunity to compare the features of calibration accreditation and traceability – or lack thereof – offered by your vendor of contact temperature sensors.
Remember, sometimes what you don’t know can bite you a lot harder than what you do!)
In practice, an accredited certificate must be recognised in any European country that are member of the EA organisation. Different agencies and details vary by regions and countries. So, visit some of the websites for your region/country and get educated as suggested in the note above.
Traceable certificates
Companies or organisations issuing traceable certificates, must be able to document that all reference instruments used for the specific calibration is traceable to one or more primary reference laboratories. Traceable means in this case, an unbroken calibration chain from the instrument, over national accredited laboratories until the highest international level at primary reference laboratories.
About AMETEK Calibration Instruments
AMETEK Calibration Instruments is a world leading manufacturer and developer of calibration instruments for temperature, pressure and process signals as well as for temperature sensors both from a commercial and a technological point of view. The company is situated in Allerød, Danmark (near Copenhagen), including their R&D, production, sales, and service facilities.
AMETEK Calibration Instruments
Gydevang 32-34
3450 Allerød Danmark
Telefon +45 48 16 80 00
Fax +45 48 16 80 80
E-mail ametek@ametek.dk
