Calibrated Weights

Calibrated Weights are used almost exclusively for adjusting and testing – (calibration of electronic balances). We therefore call them Test weights as this is their purpose of use. Adjusting a balance means that you are intervening in the weighing system, to make sure that the display is set to show the correct nominal value. And Calibration, on the other hand you are testing whether the display is correct and documenting any deviation. Regular servicing is essential for ensuring that a balance or a weighting device performs with specification. Thus adjusting and calibration both requires test weights, which are also used with weighing instruments of all classes. These test weights are also need to be protected and finely coated thus to properly adjust and calibrate our weighing machines, weighing instruments and other weighing systems.

The International valid OIML Directive R111-2004 classifies test weights hierarchically into accuracy classes with E1 is the most accurate and M3 is the least accurate weight class. As the appropriate test weight is only classified as checking equipment if it has relevant proof of accuracy. The whole test weight range in OIML accuracy classes are E1,E2,F1,F2,M1,M2,M3. With E1 being the most accurate and M3 being the least accurate one.

Cast Iron Slotted Calibration Weights & Hangers – M1 Accuracy

The  hanger weight is a weight in itself, that also has its weight Calibrated so that the hanger can be used as part of the overall weight under test,  and will hold a number of Cast Iron slotted weights depending on its usable shaft lengths. The slotted weights are discs with slots in them and are designed to sit on the hanger. Several Cast Iron Slotted Weights may be used together to build up from a minimum weight to a maximum test load.

These weights are used to test force gauges, crane scales or other suspended weighing scales. Cast Iron Slotted Weights are primarily used to calibrate large capacity scales.

Shanker Wire Cast Iron Slotted Weights are manufactured from a high quality iron. The surface are free of cracks, pits and sharp edges. All surfaces are smooth and free of scratches, dents and pores. Weights are protected by a durable coat of paint to protect the casting from rusting.

The M1 Cast Iron slotted hanger weights (Newton Cast Iron Slotted Weights, Kilogram Cast Iron Slotted Weights)  are the most common hanger weights we sell and are suitable for testing and calibration in the 5 N / 500 g up to 200 N / 20 kg.

Cast Iron Slotted Weight Hangers:

Cast Iron Slotted Weights are typically used with a hanger that also has its weight calibrated so the hanger can be used as part of the overall weight under test. Weight hangers are available in a variety of lengths and weight capacities. Hangers are calibrated to a mass value, and also have a capacity of how much weight can be loaded onto them.

Calibration Weight Certification:

You will normally need a calibration certificate to satisfy, if the tests that you do are on equipment that can effect the quality of your product and you are audited by an outside organization. Our Calibration Laboratory is NABL accredited in accordance with the standard ISO/IEC 17025 : 2017, So you can be satisfied with the quality and accuracy of the Cast Iron Newton Slotted Weights and Hangers.

Construction and General Shape:

Cast Iron Slotted Weights have adjusting cavities. Each weight has its nominal value cast into the topside of the weight. Weights are protected by a durable coat of paint to protect the casting from rusting.

Click here to enquire about Cast Iron slotted Weights and Hanger:

https://www.slotterweight.com

Metrication in Weighing & Measuring System in India

WEIGHTS play a vital role in the Society. Normally we use it to judge the cost of products while selling or buying. During the ancient period transactions of commodities were being made either through the “Exchange” or “Barter” system which failed to satisfy the need of a common man of the Society. It laid down the foundation of a system of weighment and measurement. But every social structure/Elaka (region) period gave rise to their own system throughout the whole world which could satisfy their local needs to some extent only but failed to cope up with inter-regional/ inter-state or international trade as the world was coming closer very fastly.

The French Scientists encouraged by the revolution; assigned themselves to the task of evolving a system using nature as model and natural phenomena as guide to discourage the national/regional susceptibilities, if any. The credit goes to Talleyrand, that in 1790, the French Constituent Assembly took the initiative and entrusted the uphill task of establishing a Weighing/Measuring unit/system which may have global acceptance.

After careful examination of various reports submitted by groups of leading scientists of that era, 1/10th million part of a quadrant of the earth’s meridian was adopted as the unit of length “The Metre”. The unit of mass was derived from this unit of length by defining a “Kilogram” as equal to the mass of water at its freezing point having a volume of a decimetre (1/10th of a metre) cube.

Based on the conclusions of aforesaid observations, two physical prototype Standards of Platinum one for ‘Metre’ and other for “Kilogram” were constructed and deposited in the Archives of the French Re public in 1799. Despite the fact that the “Metric System” was the most scientific and its fractions & multiples were based on decimal system, it could not get wide range acceptance by all the advanced countries due to their own socio-political reasons. Many learned scientists of France as well as other European Countries advocated and raised their voice in favour of a uniform measuring system based on “Metric System”, the system remain dormant for several years.

In 1870 the French Government took the initiative and organized a convention in Paris which was attended by 15 countries. In 1872 another convention was held with the participation of delegates from 30 countries, 11 of whom were from American continent. Finally on 20th May 1875 a “Convention du Metre” was signed by 18 countries. The signatory states not only bound themselves with the adoption of Metric system but agreed to form a permanent scientific body at Paris. Thus Bureau International des poidsetmeansures (BIPM) came into existence. So manifest were its advantages that by 1900 as many as 38 countries adopted this system in principle. This figure was doubled in the following fifty years.

Despite having all the positive aspect this “Metric System” could not be conceived and encouraged by the then “British Rulers” of India, rather they encouraged the “Zamindars” the local rulers to develop their own system of weighment and measurement. This was nothing but the famous “Divide & Rule” policy which kept these so called local rulers separate and discourage them coming on a common platform with a common uniform sense of understanding

But this phase could not last long. The interim Govt. adopted a resolution (Resolution No. 0-1-Std (4) 45 dt. 3rd Sept. 1946) which laid the foundation of National Standards Body. The purpose of this body was “to consider and recommend to Govt. of India National Standards for the measurement of length, weight, volume and energy”.

Indian Standard Institute started functioning in June 1947. Dr. Verman, the then Director of the Institute prepared a report in which he advised to adopt the Metric System and its fractions and multiples with Indian nomenclature. Just after independence a sample survey was con ducted which revealed that at least 150 different types of weight system were in use in different parts of the country Strange to note that most of these weights were having the same nomenclature but differ in actual weight markedly For example more than 100 types of “mounds” were in use ranging from 280 “tolas” to 8320 “tolas” a piece in Weight as compared to the standard mound of 3200 tolas. This system was traditional bound and not only exploiting the illiterate people but also encouraging the way to certain known malpractices. For instance, while buying the products from the producers they use the “Seer/mound” of higher weight value where as a lower weight value of Seer/mound were used while delivering these things to the consumers. In both the cases the powerful “Trader body” was benefited. It was felt by our national leaders that unless an uniform scientific system of weighment  & measurement is adopted the interest of the producers as well as consumers cannot be fully protected which was essential for the sound economic growth of the society and the country as a whole.

To implement the uphill task for introducing a systematic and uniform way of weighment and measurement, a Central Metric Committee was constituted under the chairmanship of Union Ministry of Commerce and Industry with several Central Govt. dept., State Govt. Scientists Technocrats, representatives from trade and industry as well as ordinary consumers as its members

After several meetings, marathon discussion and taking several aspects and arguments of different participants in consideration, the “Metric System” came into effect. A resolution was passed by both the houses of Parliament. On 28th December, 1956, it got consent of the President of India with the remarks that “An Uniform System of Weighing & Measuring in metric be introduced throughout all the states and union territories of India”

The Indian Standards Institute was entrusted to prepare the Standards of Weights & Measures & the Indian Weights & Measures Act 1956 was promulgated with the following preamble

i) To use an uniform system of Weights &Measures.

ii) To make greater order and efficiency in economic management like industrial production, trade and even in running a household.

ii) To fully protect the interest of producers and consumers.

iv) To develop trade with other countries of world.

v) To put the country on the map of matriculation in the world.

A sufficient number of enforcing officers were recruited and trained at ILM, as per provisions of the Act for better and uniform implementation of Metric system.

We are Manufacturer- Exporter of Standard Weights, Roller Weights, Cylindrical Weights, Slotted Weights, Test Weights ranging from 1 mg to 1000 kg in all accuracy classes.

Contact us here: http://www.weights-swpi.com/contact/

Why Calibration and adjustment are two separate things?

We calibrate a weighing device to understand how it behaves but we adjust the device to change its behavior. So to change the behavior of something firstly, we need to find how it is behaving by calibration and then we can adjust the same. It is important to find the device’s behavior before making any changes to its behavior. Therefore, it is reasonable and common to calibrate a weighing device without adjusting it.

A relationship is developed between a known value (standard) and a measured value by the help of calibration.

 Adjusting a balance means that you are intervening in the weighing system, to make sure that the display is set to show the correct nominal value. And Calibration, on the other hand you are testing whether the display is correct and documenting any deviation.

 For all units of measurement, there are some standards established as the basis for a particular unit.  In the context of weighing devices, standard come in the form of Test Weights. The Test Weight is only classified as checking equipment if it has relevant proof of accuracy.  The Test Weight has a certified value and the weighing device is supposed to indicate a value of Test Weight once it is placed upon the weighing device’s receptor. This is how we understand the behavior of the weighing device by calibration using Test Weight of certified value.

 We find a relationship between the certified value of Test Weight and the value indicated by the weighing device and finally we can also make analysis on the behavioral aspects of the weighing device.

Selection of appropriate Test Weight is very necessary for your balance. A balance can never be more accurate than the Test Weight used to adjust it, it depends on its tolerance. Accuracy of the Test Weight should correspond to the readout of the balance, rather than something better. SWPI’s Cast Iron Test Weights are intended for use in the Verification or Calibration of Weights and for use with weighing instruments of medium accuracy class or ordinary class. They are manufactured from high quality cast iron and are free of cracks and pit. 

The proper selection of an appropriate Test Weights involve knowing their proper permissible error limit, which are already set according to the OIML standards according to their class. Test Weights manufacturing as per OIML Recommendation R-111 is our specialty. Shanker Wire Products Industries (SWPI) manufactures exclusively Test Weights since 1961.

The surface quality of the Test Weights also plays an important role in the calibration of the balance. The bottom surface of Test Weight should be perfectly levelled so that it touches the receptor in its totality. SWPI’s Test Weight are well known for its Test Weight with satisfactory surface quality which ensures the accurate calibration of the weighing device.

Adjustment is not calibration. You can calibrate a measurement device without adjusting it. Calibration is developing an understanding of a measurement device. Calibration should include the determination of the measurement uncertainty to enhance the understanding of the measuring device.

To enquire about our Calibrated Test Weights follow the link: http://www.weights-swpi.com/contact/

OIML Systems

Basic and MAA Certificates registered

2015.12–2016.02

Information: www.oiml.org section “OIML Systems”

The OIML Basic Certificate System

The OIML Basic Certificate System for Measuring Instruments was introduced in 1991 to facilitate administrative procedures and lower the costs associated with the international trade of measuring instruments subject to legal requirements. The System, which was initially called the “OIML Certificate System”, is now called the “OIML Basic Certificate System”. The aim is for “OIML Basic Certificates of Conformity” to be clearly distinguished from “OIML MAA Certificates”. The System provides the possibility for manufacturers to obtain an OIML Basic Certificate and an OIML Basic Evaluation Report (called “Test Report” in the appropriate OIML Recommendations) indicating that a given instrument type complies with the requirements of the relevant OIML International Recommendation. An OIML Recommendation can automatically be included within the System as soon as all the parts – including the Evaluation Report Format – have been published. Consequently, OIML Issuing Authorities may issue OIML Certificates for the relevant category from the date on which the Evaluation Report Format was published; this date is now given in the column entitled “Uploaded” on the Publications Page. Other information on the System, particularly concerning the rules and conditions for the application, issue, and use of OIML Certificates, may be found in OIML Publication B 3 OIML Basic Certificate System for OIML Type Evaluation of Measuring Instruments (Edition 2011) which may be downloaded from the Publications page of the OIML web site.

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Magazine: “Weights & The Society” Volume: 06 & Issue No.: 1

Logo of SWPI    Magazine: Weights & The Society (Volume: 06  & Issue No.: 1)High Denominational Weights

           Published by Shanker Wire Products Industries

 

                                             

                                     GOLDEN JUBILEE CELEBRATIONS OF METRIC SYSTEM IN INDIA

“Legal Metrology – Achievements of India and what it can offer to others.”

Article by:

Sri P.A Krishnamurthy,

Former Director, Legal Metrology,

Government of India.

 

 

 

INTRODUCTION:

The field of ‘Legal Metrology’ or Weights and Measures’ as is known in the common parlance, is the field where measurements are regulated by Government laws for the benefit of all stakeholders. The main object of such regulation is to ensure standardized procedures for calibration acceptable to all stakeholders, transparency in the whole procedure, and accountability of the measurement results. Continue reading “Magazine: “Weights & The Society” Volume: 06 & Issue No.: 1″