Series AT21823 ATEX/IECEx Approved 1823 Differential Pressure Switch

Brand: Dwyer Instruments, LLC

Essential for industrial environments, the ATEX/IECEx approved Series AT21823 combines small size with 2% repeatability.

Set point adjustment inside the switch allows for set point settings across 9 ranges from the low of .07 in w.c. to a maximum 85 in w.c. differential pressure. 

Series AT21823 flame-proof enclosures are available in aluminum and are ideal for low pressure hazardous area applications. Various housing options such as an overpressure relief valve or external setpoint adjustment knob are available.

External setpoint knob allows adjustment without opening the enclosure.

Important notes for installation:
  • Cables must be fitted through 1/2" NPT cable gland or ATEX/IECEx conduit (not supplied with instrument).
  • Make sure after cabling to close tight cover and cable gland, in order to keep IP66 rating (IP65 with option OPV, overpressure relief valve).
  • Open cover only after de-energizing instrument.
  • Attention: Check local safety rules and warnings on unit and manual for a correct use of the instrument in hazardous area.
  • Compact size and repeatability, provides a high-value switch for many industrial applications
  • External setpoint knob provides easy access that simplifies making adjustments without opening enclosure
  • Flame-proof ATEX enclosure protects the device in hazardous areas


Actuator Type

  • Knob Adjust

Adjustment Type

  • Factory Set (Pre-Set)
  • Field Adjustable

Ambient Temperature Range

  • -29° to 82° C (-20° to 180° F)

Approvals & Certifications

  • ATEX
  • CE
  • IEC Ex

Diaphragm Material

  • Buna-N
  • Silicone
  • Silicone-Free

Electrical Connectors

  • Two 1/2” NPT Female

Electrical Rating

  • 15 A at 120-480 Vac, 60 Hz Resistive, 1/8 hp at 125 Vac, 1/4 hp at 250 Vac, 60 Hz

Enclosure, Body Material

  • Aluminum

Environmental Protection

  • IP65
  • IP66

NPT Connection

  • 1/8” NPT Female

O-Ring Material

  • Buna-N
  • Silicone Rubber
  • Silicone-Free

Process Connection Material

  • 316 Stainless Steel
  • Brass

Proof Pressure

  • bar: 1.7
  • kPa: 172.37
  • psig: 25

Set Point - Decreasing

  • Inches WC: 0.08 to 85.0

Set Point - Increasing

  • Inches WC: 0.08 to 85.0

Switch Type

  • SPDT

System Pressure

  • bar: 0.68
  • kPa: 68.95
  • psig: 10

  • Hazardous Area Pressure Switch
  • Process Applications
  • Mechanical Equipment Control

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