Series A3000 Photohelic® Pressure Switch/Gage

3-in-1 Indicating Gage, Lo-limit and Hi-limit Control

General Information :

The SERIES A3000 Photohelic® Switch/Gages function as versatile, highly repeatable pressure switches combined with a precise pressure gage employing the time-proven Magnehelic® gage design. The Photohelic® switch/gage measures and controls positive, negative or differential pressures of air and compatible gases. Standard models are rated to 25 psig (1.7 bar) with options to 35 (2.4) or 80 (5.5 bar) psig. Two phototransistor actuated, DPDT relays are included for low/high limit control. Easy to adjust set point indicators are controlled by knobs located on the gage face. Individual set point deadband is one pointer width – less than 1% of full scale. Set points can be interlocked to provide variable deadband – ideal for control of fans, dampers, etc. Gage reading is continuous and unaffected by switch operation, even during loss of electrical power. Choose from full scale pressure ranges from a low 0-.25 in (0-6 mm) w.c. up to 30 psi (21 bar).


  • Air conditioning systemsAir Velocity with Dwyer Pitot Tube
  • Clean rooms
  • Fume exhaust systems

Service: Air and non-combustible, compatible gases.
Wetted Materials: Consult factory.
Housing: Die cast aluminum case and bezel, with acrylic cover, Exterior finish is coated gray to withstand 168 hour salt spray corrosion test.
Accuracy: ±2% of full scale at 70°F (21.1°C). ±3% on -0 and ±4% on -00 models.
Pressure Limits: -20˝ Hg. to 25 psig (-0.677 to 1.72 bar). MP option; 35 psig (2.41 bar), HP option; 80 psig (5.52 bar). 36003S – 36010S; 150 psig (10.34 bar). 36020S and higher;1.2 x full scale pressure.
Temperature Limits: 20 to 120°F (-6.67 to 48.9°C) Low temperature option available.
Process Connections: 1/8˝ female NPT.
Size: 4˝ (101.6 mm) dial face, 5˝ (127 mm) O.D. x 8-1/4˝ (209.55 mm).
Weight: 4 lb (1.81 kg).
Switch Type: Each setpoint has 2 Form C relays (DPDT).
Repeatability: : ±1% of full scale
Electrical Rating: 10A @ 28 VDC, 10A @ 120, 240 VAC.
Electrical Connections: Screw terminals. Use 167°F (75°C) copper conductors only.


  •  3-in-1 instrument allows the reduction of several instruments with one product, saving inventory, installation time and money
  • Patented design and 1% full scale dead band provides quick response to pressure changes means no delay in switching and chatter-free operation
  • A wide range of models that can meet pressure measurement specifications from low to very high


A3000 – IOM

Catalog :

A3000 – Catalog

GOST-R Certificate


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