The Dwyer 1211 series slack-tube roll-up manometer measures static, vacuum, and differential pressure of air and gas in fan and blower tests, gas pressure evaluation, and calibration applications. The manometer has an acrylic plastic top, connectors, and over-pressure traps for use with testing air and gas, and vinyl tubing for use with mercury (sold separately) or water with fluorescein green concentrate (sold separately). The manometer is calibrated in inches of water using water and is suitable for use with mercury or water with fluorescein green concentrate measuring fluids (sold separately). The connectors accept 1/8" tubing and can be turned to seal the fluids during storage or transport. The flexible spring-steel scale is mounted between the columns to eliminate parallax reading errors, and the 2" sliding zero adjustment provides zeroing capability. The manometer has a maximum intermittent total pressure of 50psi and vacuum up to 20 inHg. The manometer can be hung or mounted using the attached magnets.

H is height, the vertical distance from the lowest