Technical data
Pressure connection
External thread G 1/2″ (pressure gauge connection) according to DIN 16 288
and internal thread G 1/4″ according
to ISO 228 Part 1.
Switching device
Robust housing (300) made of seawater resistant die cast aluminium GD Al Si 12.
Protection class
IP 65, in vertical position
Pressure sensor materials
Pressure bellows and all parts in contact
with medium X 6 Cr Ni Mo Ti 17122 Material no. 1.4571
Mounting position
Vertically upright and horizontal
Max. ambient temperature
at switching device
–25 to +70 °C
Max. medium temperature
The maximum medium temperature at the pressure sensor must not exceed the permitted ambient temperature at the switching device. Temperatures may reach 85 °C for short periods. Higher medium temperatures are possible provided the upper limit at the switching device is ensured by suitable measures (e.g. siphon).
Plastic coating
The die cast aluminium housing in GD Al Si
is chromated and stove-enamelled with resistant plastic. Corrosion tests with 3% saline solution and 30 temperature changes from
+10 to +80°C showed no surface changes after 20 days.
Contact arrangement
Single pole change over switch.

Calibration
The DNS and VNS series are calibrated for falling pressure. This means that the adjustable switching pressure on the scale corresponds to the switching point at falling pressure. The reset point is higher by the amount of the switching differential. (See also page 23, 1. Calibration at lower switching point).