Appendix A Glossary

Page A.8

Transducer A device which converts a physical quantity (such as temperature or
pressure) to a voltage or some other electrical quantity that can be
measured and analysed.
U
Upload To receive data or programs from another instrument. (Opposite of
Download).
V
Viscosity In a liquid, the resistance to that force which tends to make the liquid
flow.
Volume flow rate The rate at which a given volume of fluid flows through the system.
VOS Velocity of Sound
W
Wizard One of the “standard” configurations whch you can select instead of
configuring the 7951 from scratch. You can edit the resulting
configuration to meet your requirements.
Wobbe index A measure of the amount of heat released by a gas burner of constant
orifice. It indicates the quality of the gas and is given by the expression
2
1
V
U
Where:
V= the gross calorific value in BTU per cubic foot at STP
U= specific gravity.