The Mitutoyo 500-154-20 ABSOLUTE 500 series Digimatic digital caliper uses Mitutoyo’s ABSOLUTE linear encoder technology, allowing the user to “set and forget” the origin. By giving an absolute reading from zero rather than the last at-rest position, this caliper facilities measurements in awkward or difficult locations.

This digital caliper has 0.295-inch/7.5-mm LCD characters and accessible function control buttons, such as Origin to set and retain the original measuring point, On/Off to automatically shut off the caliper after 30 minutes, and Zero/ABS (Absolute Scale) to zero-set the LCD display. It uses the metric measuring system.

Although identical to dial and vernier calipers in its ability to make precise measurements, the digital caliper has an LCD which increases reading reliability. 500-154-20’s LCD also reflects all ABSOLUTE system activities. The Absolute Scale (ABS) function tracks the set origin point, even after shutoff. Once on again, the caliper can immediately start measuring, without zero resetting or concern of overspeed errors. The LCD can be "zeroed out" before making and comparing incremental measurements without having to subtract the first measurement from the second.

The 500-154-20 has the ABSOLUTE electrostatic capacitance linear encoder. It weighs 168g and measures outer diameter (OD), inner diameter (ID), depth, and step, where the butt end of the fixed jaw measures one end of a work piece before its upper/lower or inner/outer "steps" are measured. Model 500-155-20 has carbide-tipped jaws for precision OD measurements. Its metric system uses a 0.01 mm gradient. Outside jaw depth is 40 mm, inside jaw length is 21 mm, inside jaw depth is 16.5 mm, combined upper/lower jaw length is 77 mm, and beam width is 16. Range is 0 to 150 mm, LCD resolution is 0.01 mm, repeatability is 0.01 mm, and accuracy is rated + or - 0.02 mm. Also included are origin-setting, zero-setting, and on/off automatic shutoff function buttons. A Digital LCD Data Reading Hold function is available with the optional Data Hold Unit (959143), sold separately. An alarm alerts the user to low voltage, scale contamination, and counting value composition errors. A rolling thumbwheel makes fine adjustments and a thumbscrew locks the scale’s position. Response speed is unlimited. The caliper has Statistical Process Control (SPC) Data Output capability; it outputs data using a serial data interface to a computer or other dedicated recording device using SPC cable with Data Switch (959149 or 959150, depending on cable length required) or the Mitutoyo U-Wave Wireless Gage Interface (U-WAVE-T, 02AZD730C). It draws 1/4 the battery power when switched on and 1/8 the battery power when switched off. The SR44 silver oxide cell battery (938882) lasts approximately 3.5 years with continuous normal use and is recommended to maintain constant voltage levels.

Calipers measure the distance between two opposing sides of an object. They make inside, outside, depth, or step measurements, according to their type. Calipers are commonly used in architecture, metalworking, mechanical engineering, machining, manufacturing, carpentry, and medicine. The simplest calipers have two legs to mark the two points and require a ruler to take the measurement. More complex calipers use two sets of jaws instead of legs and have up to two graduated scales. Vernier, dial, and digital calipers all give direct and accurate readings and are functionally identical, having a calibrated scale with a fixed jaw and another jaw with a movable pointer that slides along the scale. The vernier caliper has a scale sliding parallel to the main scale for an additional, fractional reading to improve measurement precision. The dial caliper has a circular dial with a pointer on a toothed gear rack replacing the second vernier scale. As with the vernier, this second measurement is added to the reading from the main scale to obtain the result. The dial caliper is used for measuring size differential between two objects, as well. The digital caliper takes the same sort of differential measurements as the dial caliper by zeroing the display at any point along the slide, with an LCD (replacing the dial) that displays a single, easily read value in both English and metric units. Some digital calipers can hold data readings between measurements and send them to data collection devices.

Founded in Tokyo in 1934, Mitutoyo is a leader in the metrology field, producing high-quality measurement products, including mechanical, dimensional gauging products, focusing on micrometers, calipers, indicators, and other measurement tools, as well as output gauges, interfaces, data collectors, and analysis software. Mitutoyo formed Mitutoyo America Corporation in 1963, which is headquartered in Aurora, Illinois, with additional locations in the U.S. and Canada.

The Mitutoyo 500-154-20 comes with one SR44 silver oxide cell battery and a fitted plastic case.