Glossary

As a convenience to our website visitors, we have compiled a glossary to ensure that you are getting all of the information you need to get your precision switch and insert molding solutions. 

If you need details beyond the terms listed on this page, please Contact us for more info.

Actuation Point: Also known as the trip point or set point, refers to the point of operating of the contacts at a given pressure point. Pressure point where the contacts will close on a NO switch or will open on a NC switch.

Adjustable Range: Difference between the lowest and highest adjustable actuation or de-actuation set points of a switch.

Ambient Temperature: Temperature of the environment immediately surrounding a pressure sensing element.

Burst Pressure: This specification is the maximum over pressure condition that the switch can withstand without experiencing leakage.

Contact Resistance: Electrical resistance of a pair of closed contacts.

Dead Band: Area from slightly above zero gauge pressure to slightly below, within which sensor travel is not sufficient to reliably actuate a mechanical switch.

De-Actuation Point: Mainly on snap acting electrical switches: the point at which the electrical switch is operated on decreasing pressure.

Differential: The difference between opening (actuation) pressure and the closing (de actuation) set points.

Capacitive Load: A load which the current leads the voltage

Contact Arrangement: Refers to the type of circuit or contact form for the switch. Ex: SPST, SPDT, Normally Open or Normally Closed

Electrical Contacts: The elements in the switch that electrically respond to the media applied to the actuator.

Factory Calibrated Switch: The switch is not designed for field adjustment of set points. The switch can be ordered pre configured for immediate shipment or as a standard product, tailored to user needs.

Field Adjustable: A switch that has been designed for adjustment or calibration of set points in field application.

Inductive Load: A load in which the voltage leads the current

Media: Liquid or Gas the switch will be monitoring.

Motor Load: The load of a motor at rated horsepower and speed.

Operating Pressure Range: A range of inlet pressures in which the switch will operate correctly.

Pressure Switch Actuator: The member in the switch which receives the media and ultimately signals the electrical contacts to pen or close at the designated set point.

Pressure/Vacuum Switch: A device that senses a change in pressure/vacuum and opens or closes an electrical circuit when the point is reached.

Proof Pressure: The specification is the maximum over-pressure condition that the switch can have for a specified period of time and still maintain set point integrity.

Pressure Sensing Element: The portion of the switch that is in contact and moves as a result of change in pressure. The most common types of pressure sensing elements are diaphragms, bellows, bourdon tubes, and pistons.

Set Point: The pre-determined pressure/vacuum value that is required to open or close the electrical contacts in the switch.

Snap-Action Switch: A mechanically operated electric switch which, once its actuator has reached its operating (or release) point, immediately transfers to its opposite position without further travel of the actuator.

Switch Contact Forms:

Form A 1PST- NO: Single pole, Single throw, normally open

Form B 1PST- NC: Single pole, single throw, normally closed

Form C 1PDT- 1 NO/ 1 NC: Sing pole, double throw, break before make

Form X 1PST-NO DB: Single pole, single throw, normally open, double break

Form Y 1PST-NO-DB: Single pole, single throw, normally closed, double break

SPDT- Single Pole Double Throw: The switch has three terminals, one normally open, normally closed and a common terminal.

SPST-Single Pole Single Throw: Normally Closed and a common or Normally Open and a common terminal.

Switching Element- Normally Closed: A normally closed switch conducts electricity until the actuator is moved by the media causing the contacts to open.

Switching Element- Normally Open: A normally open switch does not conduct an electrical signal until the actuator is moved by the media causing the contacts to close.

Wetted Parts: Components of a switch that are directly exposed to the media.