Dear Ian Watson,

When it comes to monitoring and recording of 4-20mA signals, Lascar Electronics provides cost-effective and easy-to-install solutions from its range of USB data loggers and LCD displays.

The EL-USB-4 is a direct to USB data logger capable of recording 32,000 4-20mA samples at a rate of up to 1 per second. The standalone, battery powered data logger is connected to the loop via screw-terminals in its cap. Setup of the data logger and download of data is completed through the USB port of a Windows PC, using the software supplied with each EL-USB-4.

Lascar also has three loop powered indicators in its range. The DPM 342, DPM 742-BL and DPM 942 all provide an easy to install and cost-effective solution to displaying a 4-20mA signal.

Calibration is by two multi-turn potentiometers which allow sensitive adjustment of the instruments. The indicators have been designed to be easily commissioned with connection via screw-terminals and decimal points selected by jumper links. All three meters provide accurate, zero adjusted indication of a 4-20mA current with just a two wire connection.