Digital industrial meters constitute the largest family of automation equipment, ranging from the simplest meters that are designed only to display basic parameters such as working status or physical quantities (level, pressure etc.), to more complex control units having a number of relay outputs. The appliances of this group can be equipped with inputs for current, voltage or millivolts. There are a variety of designs: enclosures in different sizes and with displays of various sizes, or even wall-mounted enclosures, enabling the free selection of the desired type of appliance while at the same time maintaining complete functional compatibility. The additional option of current output, installed in a number of appliances, enables easy retransmission of the measured parameter to systems equipped with PLC controllers, or, for example, to other meters.