The visual display module series DZ is intended for digital displaying of analogue quantities which are usually transferred by means of electric voltage or current. It can be used especially in places where an exacting measuring and control system is not necessary or this system has to be supplemented with simple local display of the measured quantities. Right in these cases the high cover of the instrument – IP65 comes in useful, which enables operation even in bad conditions of industrial plants, boiler rooms, etc. The visual display unit can be connected to all sensors which convert the measured quantity to an analogue current or voltage output signal. The data can be calibrated in any units. Naturally, it is also possible to measure electric current or voltage themselves in the relevant range.
The instrument is built-in into a small plastic case from polycarbonate which can be mounted on a panel. The measured data are displayed on a 3.5-figure LCD display with the figure height 14 mm. The inspection window is from Perspex.
From the viewpoint of connection to the measuring circuits, these two types of visual display units are made:
• With the connector type DIN 43650 – C with a cable outlet size PG7 which enable use of a cable with the diameter max. 6.5mm. The connector is sealed and
arrested by a bolt.
• With two cable bushings size PG7. This version can be used as a “through” for the cable which is used for connecting the sensor too the control system. Conductors are connected to the screw terminal board inside the cover.
Electronics is realized by means of surface mounting technology.
The input signal can be current or voltage. The first in a two-conductor version 4÷20mA or three-conductor version 0÷10V, the second with the range 0÷10V. At an agreement it is possible to adjust also different values, especially for voltage outputs. The two-conductor version is power supplied directly from the loop and the minimal voltage drop is 8V. The current inputs are protected against overload by an inner tube fuse. For power supply of the three-conductor versions, it is possible to use direct-current voltage in the range 12÷36V. Change of the supply voltage in this range does not have a practical influence on the measuring accuracy. The instrument calibration is fixed at the producer to the required input range and corresponding visual display. Fine adjustment (by ca. ±1%) of the end points of the transfer characteristics can be made by means of trimers which are accessible after dismounting the sensor cover. The trimer for adjusting the range beginning is marked red.
