Well, it's super common in Europa related to blood alcohol content, but as a scientist or engineer you can come across it quite often. We measure water salinity in this way, thermal expansion usuallly comes in per million per degree Celsius (ppm/°C), but can also be represented as per mille (‰) when multiplied by a factor of 1000. Same with engineering strain, as a measure of deformation when an object is subject to stress. And of course tolerance of stuff the we order in a machine shop, if we need something for precision instruments, every critical measurement must be submitted with tolerances for dimensions, measurements, or performance characteristics. For example, a bearing with a radial runout tolerance of 3‰ would have a permissible deviation of 3 parts per thousand from its nominal dimension.
Well, it's super common in Europa related to blood alcohol content, but as a scientist or engineer you can come across it quite often. We measure water salinity in this way, thermal expansion usuallly comes in per million per degree Celsius (ppm/°C), but can also be represented as per mille (‰) when multiplied by a factor of 1000. Same with engineering strain, as a measure of deformation when an object is subject to stress. And of course tolerance of stuff the we order in a machine shop, if we need something for precision instruments, every critical measurement must be submitted with tolerances for dimensions, measurements, or performance characteristics. For example, a bearing with a radial runout tolerance of 3‰ would have a permissible deviation of 3 parts per thousand from its nominal dimension.
