standard conditions

Hello, In a previous video i watched, the air temperature for standard conditions was 15 degrees centigrade. I've just finished watching the Air temperature compensation video and it was stated that the air temperature at standard conditions was 20 degrees centigrade. could someone please tell me what the correct temperature is for standard conditions? cheers :)

It depends on what standard you are referring to. There are few different ones - it can be SAE, for instance. Japanese have their own STD and so on...

International standard for instrument calibration is 20 degrees Celsius, you will find laboratories at NPL are maintained within a bandwidth of 20C as are the laboratories at National Measurement Institute Australia as above some regions or secondary industries have their own standards.

Good question - as Michael said, IS is 20C but different standards use different values.

That said, it is something to watch out for as I have seen engine builders who used 0C as their 'correction', which would have given an inflated value compared to others using 20C, 60f, or whatever.

International Union of Pure and Applied Chemistry, IUPAC set the following standard conditions for gases, substances and hard matters from 1982:

Pressure 1 Bar or 100 kPa, temperature 273.15 K (0 C, 32 F)...

SAE j1349 standard makes standard air temperature at 25 C.

There are quite a few of those : DIN 70020, SAE J 1349, JIS D 1001, ISO 1585...

Thank you all for your help. I guess I've got some further reading to do :)