Danfoss A/s

Jes V Vogler

Claus Thybo

Lars Finn Sloth Larsen

Niels P Thorsen

Asbjoern Leth Vonsild

Jakob Spangberg

Jesper Hoeyer

Erling Thomsen

Jurgen W Adelhelm

Peter R Hanson

A method for calibrating a superheat sensor () for a refrigeration system is provided. The method comprises the following steps. Increasing an amount of liquid refrigerant in the evaporator (), e.g. by increasing an opening degree of the expansion valve (). Monitoring one or more parameters, e.g. the temperature of refrigerant leaving the evaporator (), said parameters reflecting a superheat value of the refrigerant. Allowing the value of each of the parameter(s) to decrease. When the value(s) of the monitored parameter(s) reaches a substantially constant level, defining the superheat value corresponding to the constant level to be SH=0. The superheat sensor () is then calibrated in accordance with the defined SH=0 level. When the parameter(s) reaches the substantially constant level it is an indication that liquid refrigerant is allowed to pass through the evaporator (), and thereby that the superheat of the refrigerant leaving the evaporator () is zero. Calibration can be performed on site, and it is therefore not necessary to calibrate the sensor () at the manufacturing facility. Thereby it is no longer required to match calibration information with a specific sensor.

Method for calibrating a superheat sensor

The invention provides a restriction element for a pressure sensor to protect the pressure element from flow related damage. The pressure sensor comprising a housing with a fluid inlet channel and a chamber with a pressure element. The pressure element comprises a housing part with a recess covered by a sealing diaphragm forming a cavity. In the oil-filled cavity a sensor element is placed. The restriction element is placed in front of the sealing diaphragm protecting the pressure element and especially the sealing diaphragm from a damaging pulse or other flow related damages caused by sudden changes in a flow system for example by closing a valve.

Pressure sensor

The invention provides a pressure sensor with a housing for a pressure sensing arrangement, e.g. a semi-conductor arrangement. The housing consists of a bottom part and an intermediate member with a through hole forming a sidewall of a cavity for the pressure sensing arrangement. A membrane is attached to the intermediate member to cover an opening of the cavity, and to allow pressure from outside to propagate into a pressure transmitting medium contained inside the housing and thus to the pressure sensing arrangement therein. The invention also provides a method of making a pressure sensor with a housing of the above-described kind.

A pressure transmitter includes a body part and a sensor unit which are joined hermetically. Adjacent to the hermetic joint, there is a gap between adjacent surfaces of the body and sensor unit, which gap facilitates an easier assembling procedure and which facilitates transportation of gases away from the hermetic joint zone when the body and sensor unit is assembled e.g. by welding.

Pressure transmitter and a method of making a pressure transmitter from a sensor unit and a body part

A pressure sensor unit having a pressure chamber formed in a housing by a plate member having a diaphragm region. The plate is fastened to the housing via an adhesive which is disposed in a joint between an inner housing surface and an intermediate support member which limits the movement of the adhesive in a direction transverse to the pressure direction.

Pressure sensor and a method for the manufacture thereof

The invention relates to a pressure responsive electric switch assembly of a type used as evaporator thermostats for refrigerators. In this unit an actuating element for operating a switch is held in equilibrium by two springs acting in opposition to a bellows which is connected to a temperature sensor capsule containing a liquid-vapor filling. An abutment arrangement is provided for the springs so that, despite a constantly rising pressure in the bellows, the actuating element operated by the bellows has a zero or null displacement range which corresponds to a substantial intermediate pressure range to which the bellows is subjected by the temperature sensor. As there is no movement by the actuating element in this intermediate range, there is an avoidance of wear which would otherwise be caused by this movement.

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Sydals, Denmark

Jes V Vogler