The heart of a quality lab or analytical balance is its load cell and suspension. The load cell should be of the electromagnetic force restoration type where the weight of the unknown is balanced out by the force generated by sending an electric current through a coil which is sitting in a high level magnetic field. The suspension should be of the Roberval type which compensates for end and side loads and allows the scale to be top loading.

The force motor should be made of the highest quality magnets and best iron in a close tolerance mechanical design. All of the units should be completely assembled in IS0-900X facilities. The suspension contains a number of flexures that are the key to a good Roberval suspension. These flexures are in essence intended to serve as frictionless pivots, and are, therefore, necked down to a very thin cross section at one point. It is interesting to note that Torbal still manufactures scales where the flexures in the Roberval suspension are taut metal bands. Torbal has over 100 years of experience in making these type of suspensions. These entire assemblies should be both “burned in” and temperature cycled. This is where basic measurement accuracy is determined, and Torbal does it all.

All Torbal scales come in cast metal housings and have heavy metal bases to prevent any warping with time or temperature. The electronics are all state of the art micro chips mounted on multilayer pc boards. All tested and burned in before final assembly. Attention to detail does make a difference. All of the front panel controls and keyboards are sealed and waterproof. All scales come with a bubble type of fluid leveling device and all use a tripod stance for stability. All scales incorporate a draft ring to minimize the effects of air currents when weighing. Some scales provide automatic internal calibration so that time and temperature have little to no effect upon the scale’s calibration, a great benefit to the user that is concerned about maintaining accuracy at all times.

Then there is the software which provides the functionality of the various scale features. Not only must it provide for ease of use, but it must be bug free. Careful testing by skilled technicians is part of the secret, but good programmers, who know their subject and write clean code, are even more important.

Look for approvals from accredited organizations like NTEP, they test rigorously to high standards.Good design benefits both the user and the supplier, the warranty comforts them.