Most calibration laboratories use procedures which allow reasonably
quick measurements to be made whilst standardizing calibration conditions.
However there is still scope for some variance in measurement results.
Most procedures allow for substitution of equipment. Some measurements
can be tedious particularly if connections have to be made and re-made
a large number of times. Difficult calculations may have to be done e.g.
from certified values of standards. All contribute to potential errors
Automated equipment is usually dedicated and completes
each task in a fixed time. It also frees up vital technician time for other
jobs. Where it becomes practical to make large numbers of measurements
random errors can be estimated. Modern instruments are often equipped with
instrument buses e.g. IEEE and fibre links, so calibration can be completely
My first experiences were of using Fluke basic to build a semi-automatic
power sensor calibrator at B.Ae(marine) It was lashed together and
gave good service provided the operator was careful to start the stepper
switch at the right setting prior to execution of the program.
I am now licensed to use Agilent VEE 6.1 and the next page contains
a graphical display of a program under development. When a development
program has been completed and thoroughly tested it can be tidied up to
the panel program with only input functions. The ability to work with a
graphical user interface enables it to be programed easier than any listed
programs. The VEE runtime version may be distributed freely with any completed
programs. I intend to build up equipment to interface with the computer
to enable a wide variety of measurements to be made.The operation of a
8560A spectrum analyser via the IEEE should be enough to demonstrate the
usefulness of the system. I have constructed a portable computer
for any customer demonstrations that may be required.
VEE Developer Display