Primary instrument

A primary instrument is a scientific instrument, which by its physical characteristics is accurate and is not calibrated against anything else. A primary instrument must be able to be exactly duplicated anywhere, anytime with identical results.

Example

  • Pressure. A U tube filled with water is a primary instrument as the water column differential is unchangeable as water is a basic physical substance. It is accurate due to its nature. Similarly a liquid in glass thermometer is a primary instrument as temperature change causes change in height of mercury column differential of which is unchangeable.

Secondary instruments

Secondary instruments must be calibrated against a primary standard. For example:

  • a dial bourdon tube type pressure gauge must be calibrated against a water or mercury U tube to assure good accuracy.
  • Time. The earth moving in its orbit is primary. Clocks must be calibrated against it.


gollark: So, apparently, reactors running on multiple fuels is a problem so vast that it needs changes to the mod to "balance".
gollark: (May not actually happen but I disagree with some NC design decisions)
gollark: (Next update: removed for "balance" because of course that makes sense)
gollark: I think glowstone is the optimal cooler type for high-efficiency stuff.
gollark: The stupid thing cost several thousand glowstone and I'm using a new 600% design on a TBUox burner to waste even more.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.