The Popular Series 477 is now available with 0.1% full scale accuracy in the new Series 477A. The 477A contains a highly accurate differential pressure sensor that offers a 0.1% full scale accuracy on air ranges from 20" w.c. to 100 psid. Series 477A Handheld Digital Manometers are packed with features needed to make pressure measurements and recording faster, easier and more accurate than ever. Instantly select from up to nine of the most widely used pressure units without having to waste time and risk mistakes with tedious conversions. A non-volatile memory function enables storage of up to 20 readings - perfect for HVAC technicians making Pitot tube traverses of air flow readings across a duct. The 477A is also ideal for maintenance personnel or technicians that require a highly accurate standard to check their instrumentation or equipment to ensure proper performance.

When working in poorly lighted areas, just switch on the handy backlight feature. The manometer automatically shuts itself off after 20 minutes to minimize battery drain. Electronic zeroing means you simply touch a single key to perfectly null out any minor pressure differences. A display HOLD key freezes the current pressure for those all-too-common situations where readings fluctuate. Included is an audible alarm to warn of overpressure plus a visual alarm warning in case ambient noise levels are too high to hear the alarm. Audible alarm also confirms a value has been stored, eliminating the need to observe display during a duct traverse.

Clear, concise operating instructions for all functions are printed on the rear of the rugged extruded aluminum case for quick reference. One-piece front membrane fully protects all keys from dust and moisture; wipes clean in seconds. Detailed written instructions, a wrist strap and 9 volt alkaline battery are included.

SPECIFICATIONS
Service: Air and non-combustible compatible gases.
Wetted Materials: Consult factory.
Accuracy: ±0.10% of full scale from 60 to 78°F (15.6 to 25.6°C); ±1% of full scale from 32 to 60 and 78 to 104°F (0 to 15.6 and 25.6 to 40°C).
Pressure Hysteresis: ±0.1% of full scale.
Pressure Limits: See chart on "Ordering" page.
Temperature Limits: 32 to 104°F (0 to 40°C).
Storage Temperature Limits: -4 to 176°F (-20 to 80°C).
Display: 0.42" (10.6 mm) 4-1/2" digit liquid crystal.
Resolution: See chart on "Ordering" page.
Power Requirements: 9 volt alkaline battery. Battery included but not connected.
Weight: 10.2 oz (289 g).
Connections: Two barbed connections for use with 1/8" (3.18 mm) or 3/16" (4.76 mm) I.D. tubing for 477A-1, 477A-2, 477A-3, 477A-4 and 477A-5 only. Two compression fittings for use with 1/8" (3.18 mm) I.D. x 1/4" (6.35 mm) O.D. tubing for 477A-6 and 477A-7 only.

FEATURES

• Measure Positive, Negative, or Differential Pressures.
• Instant Selection from up to Nine English/Metric Units.
• Stores 20 Readings in Memory for Later Reference.
• Both Audible and Visual Overpressure Alarms.
• Operates up to 100 Hours on a Single 9 Volt Battery.