My two pressure gauges for Schrader and Presta valves don't work with a Woods valve. Indeed it appears that the only way to get an idea of pressure would be to inflate it with a pump which has an integral pressure gauge. However, I think this might be rather inaccurate since the pressure difference to force the air through the valve would not be measured.
Between 2 April and 9 April the tyre appeared to be settling down after being inflated before delivery to me. The 12 calibrations between 12 April to 26 April which I reported at first post in this thread showed the calibration constant was increasing steadily by 1.55 cts/km per day. The temperature coefficient was -1.62 cts/km per degree C.
I have now added the 9 further points to this series, which now extends for more than a month:
The daily deflation now seems to average a bit less: 1.35 cts/km per day. The temperature coefficient is unchanged; 1.56 cts/km per degree C
Note that all the points lie within about 2 cts/km of the fitted lines. So using temperature and deflation coefficients which I have determined for this tyre, I could, in principle, take a calibration on one day, and then predict the calibration at another temperature within say a week or so. However, I might be as much as 4 cts/km out. So, using these coefficients can not provide the precision and reliability that one can obtain by calibrating immediately before and after a measurement ride. Nevertheless it can be useful to know what one's tyre is doing and to be able to predict calibration constants.
Also, this type of analysis is useful for comparing one tyre with another. Tyres with lower temperature coefficients are preferable when one needs to measure on days with large temperature changes. Fatter tyres tend to have larger variation with temperature, so I have now fitted another wheel to my bike with tyre of 25 mm cross-section. I have started a similar series of calibrations, and I will report in detail when I have a few weeks of data.