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6.5 Setting up for the experiments
In the previous chapter, the capabilites and set-up of the analysers was described. In this
section, I will outline how the analysers were calibrated prior to each subject in the
methodological experiments and the basic procedure to serve as an introduction to all the
subsequent experiments on adult volunteer subjects. Changes in this exact procedure and
results of each set of studies will be outlined as separate experiments. I will present and then
discuss the initial findings after the first investigations which compared the two sampling
techniques with NO, CO2, expiratory mouth pressure, and (in the t-piece system) expiratory
flow results.
6.5.1 Set-up and calibrations
These instructions were set out by Carolyn Busst and myself after many individual tests of the
machinery and then posted next to the NO analyser to follow each time I did these studies to
ensure a standard procedure. I have re-presented them here as they were written in the present
tense and with numerical representation of the recorded numbers for times and frequency or
repetitions, but have added in italics some additional notes that came to be part of the set-up
as I progressed through and became more experienced. There was no change to the nature of
the investigations, but made it easier to standardise the machines and have the set-up running
efficiently. The purpose of these procedures was two-fold; to calibrate the analysers, in
particular the NO and COz analysers, and to mark the levels on the chart recorder to enable
calculation of the study parameters.
One hour before the study:
1. Check that the NO analyser and the vacuum pump are switched on and that the ozone
generator in the analyser is switched on (toggle switch left hand side, front panel). [NB: I
found the analyser and vacuutn more stable and took less time to reach a stable level if I
let it run continuously Monday to Friday or over weekends as well if experiments were
being underraken. This is in keeping with how it would have been used oiginally as a
continuous monitor of air NO pollution.l
2. Switch on the capnograph (switch located at the back of the machine).
g. Switch on the electrospirometer (switch located at the back of the machine).
4. Check that the calibration gas cylinders and air cylinders are not empty'
S. Check the paper in the chart recorder. If in doubt regarding having sufficient to record the
whole next subject experiment, replace with a new roll. Keep the old ones for test runs.
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