230-7410 & 230-7420 Mercury Barometers (Discontinued)

IMPORTANT NOTE: Barometers containing mercury can no longer be shipped to many locations--including California, Connecticut, Maine, New York, Rhode Island, and Vermont. Due to the increasing regulation regarding the shipment of products containing mercury, NovaLynx is no longer able to offer this product. A limited supply may still be available directly from the manufacturer. For more information, please contact Princo Instruments at 1-215-355-1500, or contact us for assistance with selecting a replacement instrument suitable for your application.

The Fortin type barometer consists of a long glass tube sealed at one end and filled with mercury. The tube is inverted so that the open end is submerged in a cistern of mercury. The height of the mercury in the tube is a measure of the atmospheric pressure acting on the mercury in the cistern. Readings are taken by first adjusting the mercury level in the cistern to a zero point and then moving a vernier to the top of the mercury column.

The 230-7410 Series National Weather Service Type Mercury Barometers are the standard high quality design used by weather services and airports around the world. The vernier adjustment knob on these instruments operates through a rack-and-pinion drive to ensure smooth movement and precise setting. Models 230-7410 and 230-7411 are suitable for use between sea level and 3,000 feet. The high-altitude Model 230-7415 can be used to 12,000 feet. The accuracy of these barometers is ± 0.01" Hg, 0.3 mb, or 0.2 mm Hg, after temperature and gravity corrections are applied.

The 230-7420 Series Nova Mercury Barometers are designed for laboratory and classroom use and they feature more economical construction. The vernier is moved manually. These full-range barometers can be used at elevations to 10,000 feet.

In both types, observations are made easier by white reflectors mounted behind the cistern and the mercury column. Scales are etched for vernier readings to 0.01" Hg, 0.1 mm Hg, or 0.1 mb. An accurate dual-scale thermometer (°C and °F) is mounted on the barometer case to assist in temperature corrections. Calibrations are traceable to national standards.

The barometers are shipped completely assembled and ready for use. They are designed so that mercury can expand and contract during shipment without admitting air into the tube.


  • Measuring range:
    • 230-7410: 25.5 to 31.7" Hg, 647 to 805 mm Hg
    • 230-7411: 861 to 1068 mb, 647 to 805 mm Hg
    • 230-7415: 16.7 to 31.7" Hg, 424 to 805 mm Hg
    • 230-7420: 20 to 31.1" Hg, 508 to 794 mm Hg
    • 230-7421: 677 to 1062 mb, 508 to 794 mm Hg
  • Resolution: 0.01" Hg, 0.1 mm Hg, 0.1 mb
  • Operating elevation:
    • 230-7410 and 230-7411: 0 to 3,000 feet
    • 230-7415: 0 to 12,000 feet
    • 230-7420 and 230-7421: 0 to 10,000 feet
  • Thermometer ranges: -25° to +50°C, -10° to +120°F
  • Dimensions:
    • 230-7410 Series: 3.5" W x 42" H (89 x 1067 mm)
    • 230-7420 Series: 3" W x 40" H (7 x 1016 mm)
  • Weight/shipping:
    • 230-7410 Series: 7 lbs/15 lbs (3 kg/7 kg)
    • 230-7420 Series: 5 lbs/11 lbs (2.3 kg/5 kg)

Ordering Information

Due to the increasing regulation of products containing mercury, this product has been discontinued.

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