The Fortin’s barometer is most widely used and is generally the most accurate of the mercury barometers.
Our device is a superior standard mercury barometer suitable for altitudes up to 600 meters.
A glass tube with a nominal bore of 7 mm is encased in an enameled and lacquered brass tube and is mounted on a polished wooden board.
There is a provision for wall mounting.
With chemically engraved silver scales graduated in both millimeter and 1/10 inch, accompanied with a vernier having a least count of 0.05mm of Hg and 0.002 inch of Hg.
The vernier calliper moves with a rack and pinion arrangement and is mounted between the two scales, and the complete arrangement is enclosed in a glass cylinder.
The range of the scales= 675 to 810 mm of Hg and 26 to 32 inch of Hg.
A white reflecting surface behind the scales facilitates easier reading.
The glass cylinder, towards the lower end of the barometer has an ivory pointer with an adjustment screw.
The level of mercury in the glass at the bottom of the barometer cistern is adjusted to a scale zero, known as the fiducial point, each time a reading is to be taken. The level of mercury in the column is then read against the scale, using a vernier adjustment for extra accuracy.
A ring support and three locking screws at the base of the instrument provide the means of securing the barometer in a vertical position.
The barometer is fitted with a thermometer with a range of -10° to +50°C, to measure the ambient temperature.
The apparatus is supplied complete with working instructions.
The barometer is supplied without mercury.