Setting Up an Analytical Balances
An analytical balance is a beam balance that has an incredible amount of precision. It is used in scientific laboratories across the globe as a tool for weighing chemicals. It is most often used in quantitative chemical analysis. It can typically measure the mass of an object to an accuracy of plus or minus .0001 grams. However, analytical balances can usually only measure small samples up to 320 grams.
The weighing pans that are used for such high precision weighing are enclosed inside transparent enclosures with doors. This is to prevent dust from collecting inside the pans and affect the weight measurement. The dust can also affect the parts that are used for weighing – such as knives and bearings. Metallic dust is especially harmful to these parts. The enclosure also keeps air currents inside the room from affecting the operation of the balance. Analytical balances are extremely sensitive and because of this sensitivity, they must be used and maintained properly.
When a laboratory orders an analytical balance from a reputable retail provider, it is important to assemble the balance properly. There are incredibly important knife-edges and delicate parts that should all be packed separately for shipping. When assembling a balance, it is important to move slowly and carefully and steady your hands against a solid object. Make sure before you start that you know where all the parts go and how to get them in place without extreme force. Be extremely careful of the knife-edges that should be packed separately. A tiny blow of these knifes against any edge can ruin them.
Other factors to consider before and during assembly are that the balance should be solidly and very firmly supported on a bench or table. This bench or table should be mounted to the floor or to the wall for extra support. It should be placed in a location free from vibration. Some balances come with built-in vibration dampers but if not, mounting it on a heavy slab with sponge rubber cushions to eliminate vibration is recommended. The balance should also be protected from air currents and temperature. When the door on the balance is opened it should not have any exposure to wind or drafts. It should be away from flames, chemicals and extreme temperatures so that convection currents cannot set up inside the enclosure and affect the measurements. Even high-powered lamps can cause a temperature change great enough to get the balance off. A 30 to 50 watt lamp a few feet from the case should not cause any great problems.
In order to protect the balances from dust, temperature and air currents many laboratories have found it advantageous to install rooms, with air conditioning for maintenance of constant temperature and humidity. This just depends on the level of accuracy your lab might need from the analytical balance.
Any scientific laboratory or other entity needs to take all of the above into account when unpacking, determining a proper location and setting up the balance to ensure proper weighing and mass measurements of these small compounds and chemicals.