HansHolt
some fever
Canon EOS 6D - f/8 - 1/80 sec - 100 mm - ISO 2500
- for challenge Flickr group: Macro Mondays,
theme: Back In The Day
- A medical thermometer is used for measuring human or animal body temperature. The tip of the thermometer is inserted into the mouth under the tongue (oral or sub-lingual temperature), under the armpit (axillary temperature), or into the rectum via the anus (rectal temperature).
- Mercury-in-glass thermometers have been considered the most accurate liquid-filled types. However, mercury is a toxic heavy metal, and mercury has only been used in clinical thermometers if protected from breakage of the tube.
The tube must be very narrow to minimise the amount of mercury in it -the temperature of the tube is not controlled, so it must contain very much less mercury than the bulb to minimise the effect of the temperature of the tube- and this makes the reading rather difficult as the narrow mercury column is not very visible. Visibility is less of a problem with a coloured liquid.
In the 1990s it was decided that mercury-based thermometers were too risky to handle; the vigorous swinging needed to "reset" a mercury maximum thermometer makes it easy to accidentally break it and spill the moderately poisonous mercury. Mercury thermometers have largely been replaced by electronic digital thermometers, or, more rarely, thermometers based on liquids other than mercury (such as galinstan, coloured alcohols and heat-sensitive liquid crystals).
- The typical "fever thermometer" contains between 0.5 and 0.3 g of elemental mercury.
Swallowing this amount of mercury would, it is said, pose little danger but the inhaling of the vapour could lead to health problems.
some fever
Canon EOS 6D - f/8 - 1/80 sec - 100 mm - ISO 2500
- for challenge Flickr group: Macro Mondays,
theme: Back In The Day
- A medical thermometer is used for measuring human or animal body temperature. The tip of the thermometer is inserted into the mouth under the tongue (oral or sub-lingual temperature), under the armpit (axillary temperature), or into the rectum via the anus (rectal temperature).
- Mercury-in-glass thermometers have been considered the most accurate liquid-filled types. However, mercury is a toxic heavy metal, and mercury has only been used in clinical thermometers if protected from breakage of the tube.
The tube must be very narrow to minimise the amount of mercury in it -the temperature of the tube is not controlled, so it must contain very much less mercury than the bulb to minimise the effect of the temperature of the tube- and this makes the reading rather difficult as the narrow mercury column is not very visible. Visibility is less of a problem with a coloured liquid.
In the 1990s it was decided that mercury-based thermometers were too risky to handle; the vigorous swinging needed to "reset" a mercury maximum thermometer makes it easy to accidentally break it and spill the moderately poisonous mercury. Mercury thermometers have largely been replaced by electronic digital thermometers, or, more rarely, thermometers based on liquids other than mercury (such as galinstan, coloured alcohols and heat-sensitive liquid crystals).
- The typical "fever thermometer" contains between 0.5 and 0.3 g of elemental mercury.
Swallowing this amount of mercury would, it is said, pose little danger but the inhaling of the vapour could lead to health problems.