Dwyer® Low Cost Differential Pressure Digital Manometer Handheld, 478A-0, -4-0-4" w.c.

The Dwyer Series 478A digital manometer provides positive, negative, and differential pressure measurements, and is used to perform single-pressure measurements and to set supply pressures, verify pressure switch operation, adjust regulators, check pneumatic systems, and computer peripherals. The meter is suitable for use with air and compatible gases, and has an accuracy of + or - 1.5% of full scale. The extruded aluminum case provides durability. The four-digit LCD displays the pressure measurement. The zero function nulls minor pressure differences before measuring, min/max display provides comparative data, and display hold retains last reading when the display cannot be seen during testing.

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.