Aplab Track-Signal Test Meter incorporates Digital Signal Processing based design to provide high accuracy and stability. It is designed for level measurement of selected frequencies. It also provides functionality of AC and DC voltage measurements. The purpose of Track-Signal Test Meter is to make adjustments, control measurements and inspections on both audio frequency track circuits of types FTGS 46, FTGS 917 and also for TI21M type track circuits (now known as BI track 300) for the measurement of eight frequencies from 5700Hz to 8500Hz for metro applications. Its compactness and battery operation render the unit particularly suitable for portable applications in maintenance and for level measurement in communication systems.