AFRISO KP EX Series, Operating Instructions Manual

Page: 61 / 87

17
Selection criteria
EN
RF ... EX / KP ... EX / PF ... EX
5 Selection criteria
5.1 Range
1. Select the range in such a way that the maximum pressure load does not
exceed 75 % of the full scale value in the case of static load and 65 % of
the full scale value in the case of dynamic load.
- This prolongs the service life of the product (as per EN 837-2).
5.2 Properties of the medium
5.2.1 Pressure surges
Pressure surges must not exceed the application range of the products.
The measuring element must not be subjected to pressure surges or sud-
den pressure changes. Such changes considerably reduce the service life
of the product. For example, pressure surges occur if the product is moun-
ted to a pump, as indicated by major oscillations of the pointer.
1. Reduce such pressure surges by installing a damper or an overload
protection device between the pressure source and the elastic measu-
ring element.
Throttle elements considerably reduce the inlet cross section which leads
to a delay of the pressure change in the measuring element. The suscep-
tibility to dirt is a disadvantage of such arrangements.
Damping elements at the movement delay the pointer motion and cause
increased wear of the movement.
Liquid filling causes a damping of the measuring element and decreases
the wear of the moving parts.
WARNING
UNSUITABLE PRESSURE GAUGES
• Only use pressure gauges which are suitable for the actual operating condi-
tions (for example, measuring range, ambient conditions, medium, materials,
over-pressure safety).
• Verify that the selection criteria as per EN 837-2 as well as all directives,
standards and safety regulations pertaining to the application are adhered to.
Failure to follow these instructions can result in serious injury or equip-
ment damage.