Technical description

The M8725 display was specially designed for hazardous areas (IIC). It replaces analog needle displays with or without limit contacts.
The instruments are available for either horizontal or vertical mounting. Values between -1999...+1999 digits can be displayed with an input signal of 4...20mA. Decimal point and input range are configured in the factory to customer needs.

The display is available in two different sizes: ½"(13mm) or 1"(27mm). Due to the display size, only the following variants are possible:

-Vertical mounting with 13mm display, with and without digital limit contacts. Type M8725-GV and M8725-V
-Horizontal mounting with 13mm display, with and without digital limit contacts. Type M8725-GH and M8725-H
-Horizontal mounting with 27mm display, with and without limit contacts. Type M8725-GHA and M8725 -HA

The limit contacts are adjustable over the entire range and switch NAMUR-signals when they exceed the limit values. Both contacts can be factory configured to N/O or N/C. Both contact outputs are galvanically separated from the measuring signal by optocouplers. The display is powered by the measuring signal of 4...20mA through which a 3,8 to 4V voltage drop occurs. With input signals of 0...20mA a certified power supply is necessary. For example, power supply Type WG17R of Knick Berlin.

Example: Temperature display and control of a vessel within the hazardous area. Input 4...20mA, display range -30,0...70,0ºC, Outputs = N/C.