Renseignements généraux

Nº de série

25186

Nº de partie

1

Nombre total de parties

1

Ou

S/O

Brevets

S/O

Description générale

metal casing, pan, spirit level casing, feet and parts/ synthetic knobs, dial casing and parts/ spirit

Dimensions

Remarque : Cette information reflète la taille générale pour l’entreposage et ne représente pas nécessairement les véritables dimensions de l’objet.

Longueur

32,0 cm

Largeur

20,0 cm

Hauteur

32,3 cm

Épaisseur

S/O

Poids

S/O

Diamètre

S/O

Volume

S/O

Lexique

Groupe

Métrologie

Catégorie

Masse/poids

Sous-catégorie

S/O

Fabricant

Ou

Mettler

Pays

Switzerland

État/province

Inconnu

Ville

Zurich

Contexte

Pays

Canada

État/province

Inconnu

Période

circa 1960's+

Canada

An example of a European made balance used as a standard by a Canadian calibration service, GJS Mass Measurement owned by George Mihailov. George Mihailov worked at Industry Canada. In 1992 he left in order to start GJS Mass Measurement Inc. He ran the business out of his home. The business compared the accuracy of masses to secondary mass standards. Rather than sending their mass standards to the National Research Council Canada to be compared to Canada's primary mass standards, companies could use GJS Mass Measurement's calibration services. The uncertainty introduced by comparing to a secondary standard rather than a primary standard was not large enough to pose a problem. The equipment used in the business was often acquired through Crown Assets. This equipment was transferred to Fisher Scientific when it purchased the company. The motivation to purchase the company was that clients had been requesting that their balances be calibrated and, in purchasing the company, Fisher could provide a service. The purchase was also beneficial to GJS since it now had a much larger pool of clients. The sale took place in August 1999. At first GJS Mass Measurement continued to use its name and was a division of Fisher Scientific. Now it is simply Mass Metrology of Fisher Scientific, part of Thermo Fisher Scientific. This collection of balances (2006.0061 - 2007.0064) serves to tell the story of a small company which was started to fill a need and then was bought out by a much larger company when they too recognized the same need. Fisher Scientific metrology has a CLAS (Calibration Laboratory Assessment Service) certificate. The CLAS program is part of the Institute for National Measurement Standards, NRC. Fisher's working standards are calibrated in relation to their reference kilograms, which in turn are calibrated by NRC against the national reference kilogram. This gives indirect traceability, which can be done for the NIST reference kilogram too.

Fonction

A precision mass measuring device used by a calibration service to verify the accuracy of mass standards

Technique

To accurately determine the mass of a quantity of substance, the reading made by a balance must be made as accurate as possible. Having a balance calibrated measures its accuracy. The balance is made to a certain level of precision but this is useless if the balance is not accurate. This balance and its companions were used in calibration procedures. They were kept in the lab and the customers' calibration weights would travel to and from the lab. The thing that distinguishes the balances is their capacities, which would determine the size of weight they were able to accommodate. The H20T balance (2007.0062) was used to calibrate weights from 1g - 10g. The Mettler K7 (2007.0061) balance was used for weights 100g - 500g. The readability of 0.1g was suitable at one point but when GJS was looking for accreditation, a better balance was needed. GJS purchased a Mettler AT 1005 Mass Comparator to replace it. (That balance is not included in this lot.) The Mettler model K-7 was a direct reading substitution type balance with a capacity of 800 grams and a precision of +/- 0.03 grams. Weights up to 101 grams are read directly on the optical scale; substitution weights of 100 to 700 grams are controlled by a knob on the side of the balance and are shown on a counter next to the optical scale.

Notes sur la région

Inconnu

Détails

Marques

silver lettering on front reads 'E. METTLER/ ZURICH/ max. 800g/ SWISS MADE' with control functions/ plate on back reads 'E. METTLER/ Zurich (Schweiz)/ Type K7/ No 25186/ 25-60C 110V/ Made in Switzerland'/ handwritten label on back reads 'Out/ of/ Service/ ML 12/13/4'

Manque

appears complete

Fini

grey hammer tone painted finish on casing and pan/ glossy black painted base / black knobs and dial casing/ plated switch and feet/ black painted spirit level/ clear colorless spirit/ grey power cord

Décoration

plated metal applique script reading 'Mettler' on front