The 202Di loop powered Rate Totalizer makes an excellent Frequency to Current Converter particularly for low frequency inputs from positive displacement or turbine flowmeters. 

Because the 202Di calculates the flow rate by measuring the time interval between input pulses, it is able to provide a very stable and accurate 4-20mA output for low frequency inputs. 

Time interval measurement also means that the 202Di will have a fast response to changes in flow rate, although the response can also be limited, where necessary, via the digital filtering.

The battery version of the 202Di is designed for operation where external power sources are not available. It derives its power from two lithium battery packs which provide sufficient power for up to 5 years. Low battery power condition is signaled to the operator by a message on the LCD and battery replacement is easily carried out in the field even in hazardous areas.

The 4-20mA output version draws its operating power from the 4-20mA loop and uses lithium batteries for back-up if the 4-20mA loop is interrupted. 

The instrument provides a 2-wire re-transmission of the flow rate. Both the 4mA and 20mA points are fully programmable so that the output can span across the entire range, or alternatively, across a small section of the operating range.

The DC powered version will operate from an external power source between 9 and 28 Volts and draws no more than 4mA. This enables the 202Di to be powered from AC mains adapters and eliminates the need to run mains voltages in the field. Lithium batteries provide back-up if the DC power is interrupted.