Product Status - Retired Dec-2023
Contact us for possible alternatives.
Description
The X138-100 provides four digitally filtered inputs which eliminate potential micro-switch problems.
Outputs are provided for individual filtered versions of the raw switch inputs (DS1a, DS1b, DS2a, DS2b) and versions of each set (DS1x and DS2x) controlled by the select inputs.
For applications with flow computers that only accept one switch input (eg Omni6000) the appropriate outputs may be wire-OR’ed together.
Features
Prover loops used to calibrate turbines in fiscal and custody transfer metering systems normally use micro-switches to define the start and end of the calibrated volume.
The module can accommodate two ‘start’ and two ‘stop’ pairs of switches.
Unfortunately micro-switches characteristically produce switch bounce (multiple transitions) typically for 10 mS as the switch operates.
This can cause the Prover computer run calculations to malfunction or cause inconsistencies with the calculated data.
A crude way to minimise this is to fit a capacitor across each switch, however for various reasons this is not a good idea e.g. high discharge current through switch leading to contact erosion and shortened switch life.
The unit may optionally be fitted with on-board LEDs which allow the detector switch closures to be observed as ‘latched’ momentary flash.