• Pressure gauge 55 mm Ø and an
• additional zero pressure indicator
• Pressure connection concentric orangled in any of four directions
• High long term stability
• Precise switching accuracy
• Rugged construction
• IEC 60529 : IP 65
• Up to four micro switches

The Densistat 55 uses a chamber filled with an identical gas as a reference. When the reference chamber and the switching enclosure are at the same temperature, a change in density in the latter will induce a pressure differential. The switching enclosure and the reference chamber are separated one from another by a metal bellow. A differential in pressure will cause a deformation of the bellow. This deflection motion is transferred via a switching rod with a switching plate to actuate the microswitch required for signaling purposes. The switching thresholds can be adjusted by way of lockable screws at the switching cam.

Provided as a supplementary function to be used whenever service is required, the density monitor has a second bellows system with an additional miniature analog indicator within the main instrument. It has a measurement range of -0.5 to 0 to 1,5 bar rel. This is provided to determine, before starting service work, whether system pressure has been reduced to zero. The second bellows system is limited mechanically to a pressure of 2 bar rel.

Up to four microswitches with double-throw contacts can be installed in the Model 55. The contact outputs for the microswitches terminate in an appropriate multi pole socket inside the junction box. The corresponding connector cable passes to the outside world through a suitable cable gland.

Densistat 55 for SF6 and other Gases with additional Pressure Zero Indicator Type: D55i0 for outdoor or indoor use The junction box cover, the cable gland, the connector cable and the plug-type connector form a unit that can easily be mounted and removed with just a screwdriver.

The pressure connection can be installed at the factory either concentric to the housing at the rear or angled in any of the four directions.

The analog pressure indicator with color-coded scale (55 mm diam.) shows the relative pressure of the SF6 gas, referenced to 20°C in the switching enclosure. If the density of the gas drops as a result of a leak, the change will be indicated by the pointer as it moves along the color- coded scale. The colors and the transition points along the scale can be specified by the customer. The microswitch response points are then calibrated to the specified values.

The arrangement of the measurement mechanism and the use of vibration-resistant microswitches eliminate any shock-induced chattering at the switching contacts.

The unit is equipped with a GORE-TEX® membrane vent to prevent condensation.

Technical Data Densistat 55i0