How to Choose An Analytical Balance

How To Choose An Analytical Balance

What Is An Analytical Balance?

An analytical balance is a very accurate electronic weighing balance with readability of 0.1mg, 0.01mg or 0.001mg, it is used for applications where high accuracy is key, such as pharmaceuticals, laboratory testing and chemical analysis. Analytical balances come with draft shields to prevent air currents affecting the results, the higher up the market you go the more features and accessories the balance is likely to have. There are many things to think about when deciding which analytical balance is right for you, and if you’re not careful you could end up compromising on something important to get something that may not be a necessity.

Analytical Balances - Things To Consider

All the areas covered below will have an impact on the suitability of the analytical balance for your application and on a key deciding factor…the price. It’s all very well saying you need a 120g x 0.01mg balance with all the applications, intuitive software, weighing in any conceivable unit and even complementing your tie (ok maybe that last one is an exaggeration!)

ENQUIRE NOW

But an all-singing, all-dancing analytical balance is going to have a price tag to match and if your budget is say, £700.00, then you need to consider what the most important features are. Look for an analytical balance that includes the key features that you need but doesn’t exceed your budget, this is an easier task than it sounds, as there is a good range of balances available and we have chosen the analytical balances that provide the best value for money for sale on our scalesandbalances web shop.

Capacity

One of the first things to think about is the capacity of the balance, how much do you actually need it to weigh up to? For instance, if you only weigh items up to 100g each, there may be no point buying an analytical balance that weighs up to 300g.

ENQUIRE NOW

You need to make sure you have a high enough capacity to weigh what you need it to, and maybe a little extra just in case, however you don’t want too much extra as this could increase the price. For example, an analytical balance with a capacity of 210g and an increment size of 0.1mg and costs £780.00+VAT, however if you were looking for something of this increment size with just a few hundred grams more capacity, you may end up looking at a high end micro-balance which would cost at least £3000.00+VAT. We have a range of analytical balances with a wide range of capacities

Division Size Or Resolution

Secondly, think about the increment size of the analytical balance. Increment size is also known as readability, resolution or division size. This is the smallest unit the balance will display i.e. 0.1mg increment size means the display on the analytical balance will increment by 0.1mg. Please note that increment size is not the same as accuracy and you will need to check the datasheet of the balance to see what the accuracy is e.g. +/- 2 divisions or alternatively give us a call for advice

ENQUIRE NOW

Accuracy

With regard to the accuracy of an analytical balance most will quote a combined maximum error of 2 divisions so if you are weighing out 100g of a fine powder and you need an accuracy of +/- 1mg, a balance with an increment size of 0.01g/10mg would not be able to tell if your powder was 1mg out and although a balance with a division size of 1mg will give you a reading that is suitable.

ENQUIRE NOW

if you take into account the maximum error or accuracy of a balance then an analytical balance with a 0.1mg resolution (readability) is required. The smaller the increment size, the closer to you will be able to get to your desired weight, although a smaller increment size will also increase the price. To clarify; the accuracy of an analytical balance is the maximum difference between the applied test weight and the displayed weight. Some manufacturers quote the accuracy on the product datasheets. No measuring device is 100% accurate but typically the accuracy of standard weighing scales in a stable environment is approximately +/- (1 x division size) throughout the weighing range but for analytical balances the accuracy can be +/- 2.divisions.

Features Or Functionality

ENQUIRE NOW

Think about what units you want it to weigh in; grams, ounces, milligrams, grains or troy ounces for example. You may need a parts counting function, so you can count very small items into a container and the balance will tell you when you have reached the correct amount. A check weighing function will confirm the item or set of items is within specification. Some balances include statistical functions. The higher-end analytical balances such as the Ohaus Explorer have a comprehensive list of features.

Where Will You Use The Analytical Balance?

You will need to consider where you will be using the balance. Given the higher resolutions of analytical balances, small things can affect your readings. Vibrations from the street outside, any drafts in the area and the temperature of the room can all have an effect on your measurements. There is a draft shield that comes with the analytical balance, will that affect where you can put it and how you weigh items?

If there is a road or other vibration sources close by, you may want to consider getting an anti-vibration work surface for the balance to be used on. If there are temperature changes, some higher end analytical balances can automatically recalibrate to remove any errors that this may cause. Electrostatic issues can have a large effect on the weighing results when weighing plastic components and other conductive parts, if this is an issue, consider using an de-ioniser to remove the static charge as an optional accessory or choose the A&D BM Analytical Balance that has a built in de-ioniser.

Accessories

ENQUIRE NOW

Some balances have density determination kits as optional extras if you are require density determination. You probably need to think about more simple things, like a traceable calibration certificates for quality procedures and in-use covers to protect the display. These are moulded to the balance, and not all models have them.