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Guide to Calibrating Laboratory Balances

The true Importance of Calibrating your Balance

One of the most commonly-asked questions that accompany the purchase of a new balance is ‘When should I calibrate it for the first time, and how often should I calibrate it afterwards?’ 

– Although this is technically two questions, they are both absolutely vital for achieving the most accurate readings from a new balance or a set of scales – any operating manual would be remiss if it didn’t mention the need for calibration within the first section.

By following a few relatively simple steps during the lifetime of the equipment, it will remain in optimal working condition for the longest possible period of time.

The bottom line is: How important is the level of accuracy your application requires?

 

How important is Regular Calibration?

laboratory calibration weights
Calibration Weights For Precision Balances

The obvious answer to this is dependant on application that the balances will be used for but as a rule of thumb, regular calibration is vitally important. Some applications require the highest degree of accuracy: gloves and tweezers should be used as even the grease from the users hands can cause inaccuracies along with other external contaminants such as dust or water vapour for example.

Regular calibration with precision calibration weights s vital. Correct weights must be used: conforming to Mass Standards E2, F1 and M1 for example to ensure that accuracy is maintained

There are a number of external factors than can affect the calibration of this type of device and as a rule of thumb, any unwanted factors that adjust the internal mechanisms of a balance or scale should be counteracted with a form of calibration.

Moving the device from one place to another, unpacking it after shipping, accidental knocks or damage, and even changes in air pressure can alter the accuracy of the equipment. If you are working in a lab where other users have access to your scales and balances, you should perform calibration on a regular basis for your own peace of mind – after all it is usually impractical for you to keep a personal watch over all of your equipment on a permanent basis.

 

When Should I Calibrate?

As mentioned above, there are a number of situations which should act as a ‘trigger event’ for you to consider performing some kind of calibration process.

When you are unpacking your brand new scale or balance, you have in effect arrived at the first opportunity to undergo calibration. Bearing in mind that the measurement product could have been manufactured a great distance away from your laboratory or place of work, the factory conditions could be very different to your working environment – its new surrounding air pressure, temperature and environmental conditions need to be factored into the measurement process in order to get an accurate reading.

Aside from this, the actual shipping process could have led to the device receiving a number of knocks through rough handling and transportation, and each impact could have had a minor effect on the measurement mechanisms. With multiple impacts, there is a good possibility that the balance would have become significantly inaccurate. When dealing with equipment that is extremely sensitive, a change in location will also lead to a difference in the surrounding levels of gravity due to its relative position from the North or South Pole, and this is another reason why it is vital to perform calibration.

 

Types of Calibration

It can be advantageous to invest in a balance that comes equipped with internal motorised calibration, and this feature provides a convenient and automated process that allows the balance to adjust itself to new surroundings with the press of a button. The convenience of this type of calibration means that users can in effect perform the process each and every time the machine is switched on.

Apart from this method, it will also usually be possible to perform external calibration for the balance, and this involves taking a weight that has already been assigned a pre-determined value – this could be 1000g or a similarly-round value. Once the balance or scales is aware of this value, it can then measure other masses against this initial reading. For absolute peace of mind in situations where external calibration needs to be used, scientific professionals should consider obtaining pre-determined calibration weights that have already been weighed and certified.

 

Considerations

Anti-Vibration Table
Anti-Vibration Table

When calibrating and using electronic balances and scales, there are a number of other factors that need to be taken into consideration – these will all increase the overall effectiveness of the equipment.

Users of sensitive equipment may already be aware that the device needs to be placed in an area that has little surrounding activity, and you should bear in mind that industrial machinery can often emit vibrations that will affect the weighing device. By ensuring that the device is resting on a surface that is completely flat (you can adjust the feet of the scales accordingly), you can also check to see that the device has been grounded by coming into contact with another metal surface to prevent static electricity from affecting the reading.

 

Our range of Laboratory Balance Accessories such as the anti-vibration table, covers and hard cases are ideal for aiding the accuracy and performance of your weighing equipment.

 

The Adam Equipment Range

Adam Equipment Laboratory Balances
Adam Equipment Laboratory Balances

Within the Adam Equipment Range of scales and balances, all of the above features have been taken into consideration to allow users to obtain accurate measurements – this applies to both their portable/compact and conventional models. Their precision balances are supplied with a high standard of automatic internal calibration for the convenience of the user, while other scales can be supplied with the certified weights that make external calibration as accurate as possible.

In this range of equipment, moisture balances are also available that are specifically designed to analyse the unique properties that accompany moisture and liquids.

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UK Made Laboratory Balances, Scales & Accessories

When Precision and Accuracy are the Most Important Factors

The Brave New World

laboratory balances from_adam_equipmentWhen you consider that the ‘science’ of chemistry only started to develop in the 17th century – some three hundred odd years ago – the journey of chemical science has been quite extraordinary, reaching a level of sophistication that would have been beyond the dreams of past generations. Carbon fibre, lightweight composites, carbon nanotubes, advanced pharmaceuticals, and the microprocessors that run our world all have chemical wizardry somewhere in their production and development.

The other facet of this exciting world of technological development is ‘absolute precision’. Whether it is the research scientist or the analytical chemist, the need for precise data and accuracy of measurements is crucial, and no less so in the case of area of laboratory balances and scales.

The Digital Age Means Greater Accuracy

laboratory calibration weightsIn the past, chemists relied on handling physical weights, and their ability to accurately read off the figures from a calibrated scale, when it came to weighing substances. These methods still have their place as fall-backs, or in remote parts of the world with few facilities, but today’s researcher is more likely to reach for a digital laboratory scale or balance to get precise and reliable measurements. Indeed, the new digital balances available are often incredibly sophisticated and the UK is fortunate to have some of the best digital laboratory equipment manufacturers in the world.

Many of the models available to researchers have USB and RS-232 connections that allow measurements to be directly harvested by an attached computer or laptop, speeding up the data-gathering process. Some models even come with audible overload indicators to prevent damage to the balance.With a huge range of accessories available such as covers, hard case, anti-vibration tables and density determination kits, you can tailor each device specifically to your requirements

In the Laboratory Or Out in The Field

hard carry case with lockIn the area of corporate or public laboratory field research portable digital scales and balances are available for on-site use, so enabling researchers to spend longer in the field collecting data rather than returning to base to begin the measurement process. Low cost compact versions can simply work on AA batteries while more high-end precision portable models work on rechargeable batteries or DC adapters.

Cutting Edge Technology

For researchers at the cutting edge of chemical know-how, products, or pharmaceuticals the demand for absolute accuracy and precision of weight measurements is, again, crucial. Investing thousands of man-hours in developing a new product only to have that work undermined by poor data measurements is not what a company, or its shareholders, will want to hear. Where the research is groundbreaking, and reputations could be at stake through peer review, then accurate and reliable measurements from robust laboratory equipment is also a must. But, as mentioned, there are British companies out there that are leaders in this field of laboratory equipment.