Yokogawa CA450 process multimeter

The Yokogawa CA450 process multimeter can also act as a calibrator for electrical and process measurements. With functions for repair, maintenance and troubleshooting of plant equipment, the CA450 is a single-unit, on-site tool that is designed to help accomplish tasks that have traditionally required two on-site measuring instruments.

The CA450 is a true RMS digital multimeter with a basic measurement and generator accuracy of 0.05% and dedicated sensor modes for direct inputs from sensors such as AC/DC clamp probes. In addition, it incorporates a number of process-related features including loop check and 4-20 mA output generation and measurement functions.

With the loop check function, designed for tests on 2-wire transmitters, the CA450 supplies 24 VDC power to the transmitter and measures the DC output in mA to an accuracy of 0.05% up to 30 mA. A HART mode with loop power and 250 ohm resistance allows HART and Brain communications to be tested. A transmitter simulator function allows transmitter I/O to be checked by sinking designated currents from the external voltage generators of the instrumentation. The 4-20 mA generator output includes span, step, auto-step and sweep capabilities.

The device can also be used to carry out operating checks and adjustments on valve positioners, including zero and span adjustment, response testing using the auto-step function, and tests for hunting, sticking/slipping and valve open/close errors. Controller programs can also be verified using the device’s 4-20 mA step generation function, which switches between 4 and 20 mA in 4 mA output steps.