Since I’m on the subject of facility, I might as well cover a few more points on data center facility, measurement and sensors. When I think about sensors, it reminded me of my first job. I used to be with a Systems Integrator, working on Plant Information Management Systems (PIMS) for refineries, gas plants, utilities, etc. I remember once, I was 120km west of Doha, Qatar, and was commissioning the PIMS system together with my customer and main contractor. It was August, in the mid-90’s. We were going through the screens and data points / tags with values collected from field instruments in the plant via their Distributed Control System (DCS).
As we review the data points, we came across a few thermocouples out in the plant indicating measurements of 54′C to 60′C. Although it was a hot summer day, a reasonable reading for those tags should be in the range of 45′C to 50′C. It was an interesting anomaly…
For a gas plant, it is very critical that the plant data collected are accurate as the data are used for planning purposes, production controls, yield accounting, and many other forms of analysis.
For a data center, data accuracy is also equally important.
Below is a graph plotting the relationship of water vapor pressure versus temperature. Note that at the normal boiling point of 100°C, the vapor pressure equals the standard atmospheric pressure of 760 Torr or 101.325 kPa (approximately 7.5 Torr per kPa), and that is where evaporative cooling takes place (water turning into gas form takes a part of the heat with it). Anyway, enough of boring details…
