Special features
     Differential pressure measuring ranges from 0 … 40 mbar to 0 ... 4,000 mbar
     High working pressure （static pressure） of 50 bar
     Overpressure safety either side up to 50 bar
     Scaleable measuring ranges （maximum Turn Down of 1 : 3.5）
     Very compact design
     Optionally compact valve manifold with working pressure

    The standard centre distance of 37 mm between the process connections can be adapted to a custom centre distance of 31 mm or 54 mm using adapters for flange mounting.

   Design and operating principle
    Pressures p1 and p2 act on the media chambers ⊕ and ?, which are separated by an elastic diaphragm （1）.

    The differential pressure （Δp = p1 - p2） leads to an axial deflection of the diaphragm against the measuring range spring （2）.

    The deflection, which is proportional to the differential pressure, is transmitted to the movement （5） in the indicating case （4） via a pressure-tight and low friction lever mechanism （3）.

    Overpressure safety is provided by metal bolsters （6） resting against the elastic diaphragm.

   Standard version

   Differential pressure gauge
    Model 712.15.160
    Model 732.15.160

   

   Illustration of the principle

   

    Mounting according to affixed symbols
    ⊕ high pressure and ? low pressure

   

   Span adjustment
    The measuring span of the differential pressure gauge can, depending on the particular measuring cell used, be adjusted within the measuring range limits given in the previous specifications table. Ideally, this adjustment should be made on a test bench, though it can also be carried out at the measuring point using a hand test pump.

   

    The span adjustment, situated at the 4 o‘clock point on the case circumference, is accessible by removing the cover cap. With the gauge subject to the desired nominal pressure, insert a hexagon screwdriver （SW 3 mm） into the funnel guide, and adjust the pointer to the final value by turning it clockwise （for a lower measuring range） or anti-clockwise （for a greater measuring range）. The gauge will then be fully adjusted to the required measuring range. If the gauge is equipped with a transmitter model 89x.44, then this procedure will also adjust the output signal to the new measuring range. After completing the adjustment the instrument should be re-sealed with the cover cap.

   Scale designs
    The dials can be made to customer‘s requirements and also with multiple scales. In addition, up to three different, interchangeable slip-on dials can be supplied, e.g. for measuring different media.
    These can be printed with all usual units on them, e.g. kg, litre, m3, mmH2O, inchH2O, % etc.. Red marks for maximum fill level, customer logos and other custom printing are likewise possible. If desired, we can carry out the calculation for the tank fuel level from drawings of the tank geometry, and then make the appropriate scales.

    Dimensions in mm

    CE conformity
    EMC directive
   2004/108/EC, EN 61326 emission （group 1, class B） and interference immunity （industrial application）

    ATEX directive 1）
   94/9/EC, II 2 G Ex ia IIC 1） Option

   Approvals
     GOST-R, import certificate, Russia
     GOST, GOST, metrology/measurement technology,
        Russia （only for model 712.15.160）
     BAM, oxygen application （only for model 732.15）

    Approvals and certificates, see website

   Option
    Valve manifold （wetted）
    with mounted working pressure gauge

   



    With a single order, all parts necessary for the fitting to the differential pressure gauge are included in the delivery: 4 x hexagon screws M8 x 16 , 2 x O-ring seal

   Option

   Switch contacts
    for level and/or working pressure indicators

    A modular system of electromechanical and electronic switch contacts with plug connection, also suitable for retrofitting on site, can be fitted both to the level display and to the working pressure indication. They consist of self-contained units, which can be fitted to any pointer pressure gauge within a few minutes. The connection to the instrument pointer is made by means of a special yoke so that a carrier pin at the pointer itself is not needed. The set value pointer of the
installed switch contacts are adjusted, from the outside, to the value at which the switching operation is to take place, using the adjustment lock with a separate or integral key. A coupler connector, an M3 x 20 centring screw and a seal are
included in the delivery.

    Switching functions
    The following applies, as a general rule, to the contact functions of the model 828 1） magnetic snap-action contacts in connection with our standard settings:Index 1 according to the contact type no. means:
    Contact closes the circuit when the set point is exceeded Index 2 according to the contact type no. means:
    Contact opens the circuit when the set point is exceeded Index 3 according to the contact type no. means:
    When the set value is exceeded, one circuit is opened and one circuit is closed simultaneously （change-over contact）

    The following applies, as a general rule, to the contact functions of the model 838 1） inductive contacts in connection with our standard settings:
    Index 1 according to the contact type no. means:
    Contact closes the control circuit when the set point is exceeded （flag disengages from control head）
    Index 2 according to the contact type no. means:
    Contact opens the control circuit when the set point is exceeded （flag engages with control head）
    The switching functions are based on a clockwise rotational motion of the instrument pointer.

   

   Dimensions in mm

   

    Option
    Panel mounting

   Ordering information
    Model / Scale range （measuring cell） / Scale design / Process connections with centre distance / Options