Span Gas Calibration Tracking

A tracking system for span gas or calibration gas has been supplied to Cummins Engines European Technical Centre at Darlington UK.

Specialised calibration gas mixtures are used by engine manufacturers for environmental compliance and engine emissions testing in order to meet required calibration standards when testing engines for production and research.

As part of the engine testing process emissions ‘carts’ are calibrated using standard span gases which are fed from different bottle stores depending upon the location of the cart. When a span gas bottle is empty it is replaced and the associated analysers are re-calibrated using the concentration specified on the new bottle.

In order to track how often bottles are changed and to ensure that carts are re-calibrated a tracking system has been introduced. New gas concentrations are recorded each time a bottle is changed and these are made available to the control system in the engine test cells so that all of the associated emissions carts can be automatically updated with concentration levels.

A touch screen operator interface in each bottle storage area allows users to enter bottle change details.

A bottle selection display on the touch screen allows a user to select the bottle to be replaced from a list of possible gas types and span gas concentrations. For example, the user could select Propane and the range 500ppm

User entry of concentration (in ppm) from the new bottle is validated to check that it is within acceptable tolerances (either absolute or as a difference from the previous entry) to minimise operator errors. User entry of Certificate Number (Inspection Lot) is also validated.

New concentrations are recorded into a database along with the current date and time, Certificate Number, and the operator’s ID.

Replaced bottles have their records identified by being marked as empty, the date and time of the removal, and the operator ID who switched out the bottle

Current span gas values are remotely accessible on networked PCs.

A report option is available to provide print outs of all bottle usage and their associated concentrations.

The current span gas concentrations and certificate numbers are made available to the associated cell control system.

An optional barcode scanner at each location can ensure that operator errors are minimised and makes user interaction as simple as scanning the bottle location (barcode attached to the wall) and then scanning the new bottle (barcode attached to the bottle indicating gas type and concentration).