Series-DHConfiguration

Multifunction Differential Pressure Controller, 0.5% Accuracy, Digital Display

3-in-1 instrument allows the reduction of several instruments with one product, saving inventory, installation time and money
Velocity of flow modes, a square root output coincides with the actual flow curve for greater precision
Power usage of 120/220 VAC or 24 VDC provides flexibility to incorporate device in control panel
Secure menu program provides access to device operation only for the right skill level
Modbus® communications supports Process and HVAC system integration and control

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Series-DH

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Data Sheet

Product Overview

Accuracy Detail ± 0.5% at 77°F (25°C) including hysteresis and repeatability.
Baud Rate 9600
Compensated Temperature, Max 140 °F
Compensated Temperature, Min 32 °F
Data Interface Modbus RTU, RS485
Display Note 4 digit LCD 0.4˝ height. LED indicators for set point and alarm status
Display Type LCD
Electrical Connection Screw Terminal
Enclosure Ratings IP66, NEMA Type 4X
Height 3.62 in
Length 1.772 in
Materials ABS
Materials, Wetted Consult Factory
Media Compatibility Clean dry air / inert gas, HVAC / room air, Inert / non-reactive gases, Helium, Nitrogen, Non-Corrosive Dry Gases
Mounting 1/8 DIN
Mounting Orientation Horizontal
Number of Digits 4
Operating Temperature, Max 140 °F
Operating Temperature, Min 32 °F
Output Detail 4-20 mA DC into 900 Ω max
Output Signal Current
Power Consumption 7 VA, Low Power: 130 mA
Measurement Pressure Type Differential
Process Connection Note Compression fitting for use with 1/8˝ ID X 1/4˝ OD tubing (3.175 mm ID x 6.35 mm OD). Optional barbed fitting for 3/16˝ ID tubing
Process Connection Size 1/8 in
Process Connection Type Compression Fitting
Response Time 250 ms
Series ID Series-DH
Set Point Adjustment Menu Configurable
Stability <± 1%/year
Supply Power Note High voltage power = 100-240 VAC, 50-400 Hz or 132-240 VDC, Low voltage power = 24 VDC ± 20%.
Supply Power Type AC/DC
Supply Voltage 100 to 240 Vac, 132 to 240 Vdc
Switch Note 8 A at 240 VAC resistive
Switch Rating 8 A @ 240 Vac
Switch Type (2) SPDT
Thermal Effects 0.020%/°F @ 77°F
Weight 14.4 oz
Zero Setting Adjustable Range Accessible via Menus

Supported Applications

The Dwyer Series DH Digihelic® Differential Pressure Controller is a multifunction instrument designed for measuring and controlling differential pressure in air and non-combustible, compatible gases. The series functions as a digital display gage, control relay switch, and transmitter with current output. It supports operation modes for pressure, velocity, and volumetric flow applications across various engineering units.

Operating Conditions & Performance

The Series DH achieves an accuracy of ±0.5% at 77°F (25°C) including hysteresis and repeatability after a 1-hour warm-up period. The instrument operates within an ambient temperature range of 32 to 140°F (0 to 60°C). Response time is specified as 250 ms with dampening set to 1.

Measurement ranges span from 0.25 in w.c. up to 100 in w.c., available via specific model selection for unidirectional and bi-directional spans. Pressure ratings vary by range: models ≤ 2.5 in. w.c. are rated at 2 psi; the 5, 10, and 25 in. w.c. ranges are rated at 5 psi; and the 50 and 100 in. w.c. ranges are rated at 9 psi.

Available Engineering Units

The controller allows selection of multiple engineering units for display, including:

Pressure: INWC (inches water column), FTWC, MMWC, CMWC, PSI, INHG, MMHG, MBAR, PA, KPA, HPA, OZIN.
Velocity/Flow: SFPM, M/S, SCFM, M^3H.

Configuration Options

The series offers configurable options for process connections, calibration documentation, and mounting. The standard enclosure is ABS plastic (UL approved 94-V-0) with a face designed to meet NEMA 4X (IP66). Electrical connection utilizes screw terminals.

Power Supply Options

High Voltage: 100 to 240 VAC, 50 to 400 Hz or 132 to 240 VDC.
Low Voltage: 24 VDC ±20%.

Output Signals & Communication

Analog Output: Scalable 4-20 mA DC into a maximum load of 900 Ω (typical 250 to 600 OHMS).
Digital Communication: Modbus® Protocol RTU over RS485 at 9600 Baud. The factory default address is 50.

Process Connections & Options

The standard process connection is a compression fitting for use with 1/8" ID tubing x 1/4" OD tubing (3.175 mm ID x 6.35 mm OD). An optional barbed fitting (-B) is available for 3/16" ID tubing.

Additional options include:

-FC: Factory calibration certificate.
-NIST: NIST traceable calibration certificate.

Key Product Differences

The Series DH is available in specific model numbers corresponding to distinct pressure ranges. Models are categorized by unidirectional and bi-directional capabilities, with velocity and volumetric flow modes not available on bi-directional range units or models DH-009 and DH-010.