- 01: Introduction
- 02: History
- 03: Propellants, Firearms, and Ammunition Development
- 04: Modern Firearms Manufacture
- 05: Small Arms Ammunition
- 06: Evidence Handling Procedures
- 07: Equipment and Instrumentation
- Introduction
- Objectives
- AFTE Knowledge and Ability Factors
- Measurement, Standards, and Accuracy
- Weight, Force, and Their Measurement
- Dimensional Data and Measurement Tools
- Muzzle Velocity of Bullets
- Stereo and Comparison Microscopes
- Small Tools and Supplies
- Imaging Equipment
- Field Support Equipment
- Computer-Based Technologies
- Firing Facilities
- Selected Bibliography
- 08: Examination of Firearms
- 09: Cartridge and Shotshell Examination
- 10: Characterization and Evaluation of Fired Projectiles
- 11: Bullet Comparison and Identification
- 12: Gunshot Residue and Distance Determination
- 13: Toolmark Identification
- 14: Communicating Results
- Resources
Digital Scales
Home > Equipment and Instrumentation > Weight, Force, and Their Measurement > Digital Scales
A digital scale used to weigh small objects
Today, examiners use a digital (electronic) scale to weigh small objects, such as bullets or bullet fragments. These instruments offer advantages over previously used technologies, including convenience, cost, speed, and accuracy.
Several components typically found in digital scales include
- multiple strain gauges,
- a load cell,
- a signal amplifier,
- a specialized microprocessor with built-in proprietary software.
Size comparison of a strain gauge
mounted on a rifle and a dime
A strain gauge is a paper-thin device that normally covers an area less than that of a dime. It can be permanently affixed to a metal surface to detect stretching or compression; the electrical resistance of the gauge changes with the stretching or compression of the metal surface.
With the exception of the microprocessor, all of the technology used in digital scales has existed for many decades. When microchips became available, the digital scale was a natural development. The proprietary software (built into the microprocessor) processes the data initially provided by the strain gauges, providing stable and useable readings.
