HELP WITH CHOOSING A SCALE TO SUIT YOUR NEEDS
Although there are many hundreds of different types of scales available to buy, it is easy to narrow your choice down to a few possibilities by considering the following points. Do realise however that you cannot have a ‘one scale fits all’ situation, certainly not if the weight ranges are widely differing.
- BASIC TYPE SELECTION - On our homepage, select the section likely to contain a product suited to your basic requirement, e.g. ‘Retail’, ‘Industrial’ or ‘Medical’.
- TRADE APPROVAL - Do the scales need to be ‘Trade Approved’. If the use of the scales is going to be the ‘deciding factor’ in the actual price charged to a customer for the weighed items, the scale must be ‘Trade Approved’, also known as ‘Stamped’, ‘Weights & Measures Approved’ or ’Class III Approved’. Medical scales as used in Hospitals, Doctors’ surgeries and Pharmacies etc. must be ‘Class III approved’ when used in relation to medication, treatment or diagnosis. A special case exists in that scales used in the Gold and Jewellery trade MUST have the more exacting 'Class II Approval'.
- CAPACITY - What is the heaviest amount that the scales will have to weigh? There is no point buying a scale having a much greater capacity than you actually need, but it is sensible to allow a fair margin of extra capacity, possibly around 40%.
- DIVISIONS - The ‘division size’ is the minimum weight difference that the scale can display as the weight on the pan increases. A division size of 100 grams for instance means the weight will be displayed to the nearest 100 grams. This is fine for weighing heavy parcels for despatch, but useless for letters! You should pick a scale with a division size small enough to suit your intended use.
- WEIGH PAN SIZE - The weigh-pan should obviously be large enough to accommodate anything that the scale is required to weigh of course, although a reasonable amount of ‘overhang’ is perfectly OK so long as the item being weighed does not touch anything other than the weigh-pan.
- CERTIFICATION - In certain circumstances, i.e. if your company is ISO accredited for instance, you will probably be required to have your scales certificated. We can provide the necessary official printed certificate stating that they have been calibrated using weights traceable to national standards.
- WEIGHING UNITS - Do you need to weigh in units other than Grams and Kilograms? If a scale is ‘Trade Approved’ (See Trade Approval paragraph above) current law states that it can only display the weight in Grams and Kilograms. If not, many scales allow you to select different ‘units’ to weigh in, most commonly Stones, Pounds and Ounces. There is a wide range of other weighing units that can be selected on some scales, mainly electronic precision balances.
- COUNTING SCALES - Many people misunderstand counting scales but they can help you so much with stocktaking! They can make this unpleasant and very time-consuming job extremely easy by removing the need to hand count more than just a few of each item to be counted to use as a sample. They can accurately count any number of items of equal weight, and the most economical machine for your intended use can usually be chosen based on the individual item weight of the lightest item you need to count, together with the maximum total weight ever likely to be put on the pan. Let us take as an example a counting scale having a capacity of 3000 grams (3 Kg.) and a 'count resolution' of 1:600,000. In counting mode the divisions are based on this 'count resolution' figure and NOT the stated division size which is only used in basic weighing mode. Dividing the scale capacity by the count resolution gives the absolute minimum change in weight that the scale can detect which in this case is 0.005 gram. If the weight of just one of the items to be counted is around ten or more times this value, then the machine will be able to give a reliable count as there will be sufficient 'steps' between each item to help it decide. In our example this machine can count items weighing 0.05 gram (50 milligrams) or more. You may of course need a scale of less or greater sensitivity and these are all available. This information will hopefully prevent you spending more than you actually need to!
We hope this page helps you to choose the right scale for your requirements. We are always available if you need more information or advice, so please feel free to call us on 01773 763555 if you need any further help.