The Tenma 72-6694 CAL D is a portable current calibrator designed for precise calibration of process devices and measurement signals. It features a large LCD display with a maximum count of 1999 digits and 13mm (0.5 inch) digit size. Powered by a 9V alkaline battery or equivalent, the device offers an adjustable current source from 0 to 24mA with two measurement ranges: 0 to 19.99mA with 0.01mA resolution and ±0.25% accuracy, and 0 to 24mA with 0.1mA resolution and ±0.5% accuracy. It can drive loads up to 500 ohms with a sampling time of 0.4 seconds. The calibrator is suitable for testing and calibrating process control devices, operating within a temperature range of 0°C to 50°C and humidity levels below 80% RH. It features an over-input indicator and comes with a 12-month limited warranty.