The Dwyer Mark II 25 inclined differential manometer with red gauge fluid has a 0 to 3 inH2O measuring range, built in zero level and molded plastic case for monitoring air velocity and air filter performance, and taking pressure measurements above and below atmospheric pressure. Red gauge fluid is freeze-proof and has lower evaporation rate for use in cold environments, and produces expanded scale viewing for improved reading resolution. The built-in zero level provides linear calibration. The manometer has a styrene-acrylonitrile housing, indicating tube, and fluid wells for strength and durability. The molded ABS knobs and zero adjust plunger and shock-mounted glass level vial are wear-resistant. Leakproof O-ring seals and overflow tank reduce the risk of fluid loss. Scales are lithograph printed on aluminum to ease reading, and are epoxy coated to protect against wear. The manometer can be mounted on any vertical surface.

H is height, the vertical distance from the lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.

Manometers measure the pressure of a liquid or gas. They are used in laboratory, medical equipment, engineering, automotive, and heating, ventilation, and air-conditioning applications. Manometers measure any combination of gauge, absolute, or differential pressures. Gauge pressure is the amount of pressure in a system relative to the ambient pressure, absolute pressure is the amount of pressure in a system relative to an absolute vacuum, and differential pressure is the difference between two pressures. Analog manometers are composed of columns of liquid, and they use gravity and the liquid's density to calculate pressure. Because they have no moving parts, analog manometers do not require re-calibration. Digital manometers have pressure sensors that are connected to a system with a hose to provide a digital readout of the amount of pressure present in a system. They use microprocessors to calculate pressure, and they require periodic calibration to help ensure accuracy.

Dwyer Instruments manufactures measurement and control instruments, including pressure gauges, flow meters, level instrumentation, temperature instrumentation, and air quality monitors. The company, founded in 1931, is headquartered in Michigan City, IN.

What's in the Box?

• Mark II 25 manometer
• Red gauge fluid, 1oz.
• Flexible double column plastic tubing, 8 ft.
• (2) Tubing connectors, 1/8"
• (2) Mounting screws
• Red and green pointer flags
• Instructions