Weighing scale
The balance (also balance scale, beam balance and laboratory balance) was the first mass measuring instrument invented. In its traditional form, it consists of a pivoted horizontal lever with arms of equal lengththe beamand a weighing pan suspended from each arm (hence the plural name ""scales" for a weighing instrument). The unknown mass is placed in one pan and standard masses are added to the other pan until the beam is as close to equilibrium as possible. In precision balances, a more accurate determination of the mass is given by the position of a sliding mass moved along a graduated scale. Technically, a balance compares weight rather than mass, but, in a given gravitational field (such as Earth's gravity), the weight of an object is proportional to its mass, so the standard masses used with balances are usually labeled in units of mass (e.g. g or kg).
Digital microscope
An early digital microscope was made by a company in Tokyo, Japan in 1986, which is now known as Hirox Co. LTD . It included a control box and a lens connected to a computer. The original connection to the computer was analog through an S-video connection. Over time that connection was changed to Firewire 800 to handle a large amount of digital information coming from the digital camera. But some of their current advanced versions are all-in-one and do not require a computer. The most advanced all-in-one systems now have HD monitors built-in.
The invention of the USB port resulted in a multitude of USB microscopes ranging in quality and magnification. They continue to fall in price, especially compared with traditional optical microscopes. They offer high-resolution images which are normally recorded directly to a computer, and which also use the computer power for their built-in LED light source. The resolution is directly related to the number of megapixels available on a specific model, from 1.3 MP, 2 MP, 5 MP and upwards.