Series DH3 Digihelic Differential Pressure Controller
Brand: Dwyer Instruments, LLCThe SERIES DH3 Digihelic® Differential Pressure Controller is a 3-in-1 instrument possessing a digital display gauge, control relay switches, and a transmitter with current output all packed in the popular Photohelic® gauge style housing. Combining these 3 features allows the reduction of several instruments with one product, saving inventory, installation time and money. 
The Digihelic® controller is the ideal instrument for pressure, velocity and flow applications, achieving a 1% full scale accuracy on ranges down to the extremely low 0.25 inches WC to 2.5 inches WC full-scale. Ranges of 5 inches WC and greater maintain 0.5% Full Scale accuracy. Bi-directional ranges are also available. 
The Series DH3 Digihelic® controller allows the selection of pressure, velocity or volumetric flow operation in several commonly used engineering units. 2 SPDT control relays with adjustable deadbands are provided along with a scalable 4-20 mA process output. 
Programming is easy using the menu key to access 5 simplified menus which provide access to: security level; selection of pressure, velocity or flow operation; selection of engineering units; K-factor for use with flow sensors; rectangular or circular duct for inputting area in flow applications; set point control or set point and alarm operation; alarm operation as a high, low or high/low alarm; automatic or manual alarm reset; alarm delay; view peak and valley process reading; digital damping for smoothing erratic process applications; scaling the 4-20 mA process output to fit your applications range and field calibration.
Features- 3-in-1 instrument allows the reduction of several instruments with one product, saving inventory, installation time and money
 - Full scale accuracy of 1% even on extremely low ranges, and 0.5% for ranges above 5 inches WC provide for greater measurement precision
 - Secure menu program provides access to device operation only for the right skill level
 
Specifications
Brand
Accuracy
- ± 0.5 % at 25° C (77° F) Including Hysteresis & Repeatability, (After 1-Hour Warm-Up)
 
Adjustment Type
- Adjustable Via Keypad on Face
 
Approvals & Certifications
- CE
 
Compensated Temperature
- 0° to 60° C (32° to 140° F)
 
Consumption
- 3 VA, Max.
 
Display
- Backlit 4-digit LCD 0.4" Height LED Indicators for Set Point & Alarm Status
 
Electrical Connectors
- 15-Pin Male High Density D-Sub Connection
 - 18" Cable (46 cm) with 10-Conductors Included (4" & 10" Cables Available)
 
Electrical Rating
- 1 A at 30 Vdc/Vac
 
Enclosure, Body Material
- Bezel
 - Die Cast Aluminum Case
 
Media
- Air & Non-Combustible, Compatible Gases
 
NPT Connection
- 1/8" NPT Female
 
Output
- 4-20 mA DC Into 900 ohms, Max.
 
Power Requirement
- 12-28 Vac, 50/400 Hz
 
Response Time
- 250 ms (Damping Set to 1)
 
Sensor Orientation
- Mount Unit in Vertical Plane
 
Set Point - Decreasing
- inH₂O: 0 to 25
 
Set Point - Increasing
- inH₂O: 0 to 25
 
Size
- Gauge: 5" (127 mm) O.D. x 3-1/8" (79.38 mm)
 
Span & Zero Adjustments
- Accessible Via Menus
 
Stability
- < ± 1 % Per Year
 
Switch Type
- 2 SPDT Relays
 
Temperature Range
- 0° to 60° C (32° to 140° F)
 
Thermal Drift
- ± 0.054 %/°C (± 0.03 %/°F)
 - 0.036/°C (0.020 %/°F) from 25° C (77° F)
 
- SCFM flow in ducts
 - Filter status
 - Static pressures in ducts or buildings
 - Damper control
 - Fan control