You will need
Before buying or ordering through a reliable online website mask, you need to know what size will suit you. There are several ways to determine the sizeand mask, depending on the method of measurement and also brand.
If you are going to purchase a gas mask with a helmet-mask (GP-5, RSH-4, PMG, PBF), know your size you will be able in two ways.
Take a centimeter and measure the length of a closed line which should pass through the crown, chin and cheeks. Then measure the length of the line connecting the ear and passing through the superciliary arches. Add the results of the first and second measurements. Round the final result to 0.5 or units.
Find out your size. So, if you got up to 92 cm, then you should purchase a gas mask the size ofa "0" from 92 to 95.5 cm – 1 in the from of 95.5 to 99 cm – "2", 99 to 102,5 cm – 3, the more 102,5 – "4".
In the second method of measuring head for a gas mask one of these brands you will be quite enough to know the length of a line passing through the crown, chin and cheeks. If the length 63.5 cm, then it will fit a size "0", from 63.5 to 65.5 cm old – to 1, from 66 to 68 cm – "2", from 68.5 to 70.5 per – "3" and more than 71 cm – "4".
If you are planning to purchase a gas mask with adjustable back elastic (GP-7, PMK), you will have to make measurements of a different nature. Take a centimeter and measure the horizontal circumference of the head (about the same as it is done in the selection of headgear).
If the circumference up to 56 cm, then you should buy a gas mask of these brands that has the size "1", from 56 to 60 cm – "2," more than 60 cm – "3".
Before finally to verify the correctness of his choice, try a mask of your chosen brand. Don't forget before fitting to remove the hair so that they do not violate its integrity.