Hymetrics Example, Device Object Technology Page

Hymetrics
Smart Environmental and Industrial Systems

Examples: Device Object Technology

The rules governing the estimation of uncertainty are set out in the 'Guide to the Expression of Uncertainty in Measurement' document , prosaically known as 'the GUM'. The GUM classifies uncertainty into two types: type-A which can be determined by the instrument itself (from the standard deviation of a sequence of measurements) and; type-B which are estimated from measurements made by the user during the installation process.

A Smart instrument should be able to do type-A estimates and to provide input variables for the user's type-B estimates, of which there may be several. From these, a Smart instrument then computes an overall uncertainty for the measurement process.

The example chosen here illustrate DOT's ability to handle type-A estimates for an ultrasonic air-range level sensor, as viewed using an Object Brower.

HEOS, example image 6.82K

Here, the significance of DOT is that the product designer can offer measurement uncertainty as an option for the user and do so without the need for 'Interoperability Rules'.

But, a role exists for interoperability rules if one device of a system is required to access the uncertainty values of another device. In which case an object defined by the word UNCERTAINTY_LEVEL might be chosen as Standard nomenclature. The device would be able to recognise the request and provide a byte-code symbol for inter-device communication.