what does hg stand for in metric system
Inch of mercury Inch of mercury (inHg and "Hg) is a unit of measurement for pressure. It is still used for barometric pressure in weather reports, refrigeration and aviation in the United States.
Imperial units British law now defines each imperial unit in terms of the metric equivalent. The metric system is in official use within the United Kingdom for most official applications with Imperial units remaining in widespread use amongst the public.[36] All UK roads use the imperial system except for weight limits, and newer height or width restriction signs give metric alongside imperial.[37]