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Honeywell DL423 DirectLine® pH/ORP Sensor Module

DirectLine® pH/ORP Sensor Module

The Honeywell DirectLine® architecture consists of an electronics module integral to the conductivity cell. This design eliminates the need and added cost of a separate analyzer or transmitter.

The electronics module is sealed in a plastic weather proof, corrosion resistant housing and is connected to the conductivity cell on one side and a 4-20 mA output cable on the other via water proof connectors. This housing design allows this system to be used in harsh environments where moisture and dust is a problem.

For special mounting applications, the remote mounting option connects the electronics module to the conductivity cell via a cable. The electronics module is then mounted on a 2-inch pipe, wall, or DIN rail.

• Direct 4-20 mA output eliminates need for dedicated analyzers or transmitters, simplifying installation, start-up, operation, and maintenance tasks. Installation costs are also reduced because standard cable can be used for additional cable distances.
• Automatic upload of cell constant and cell calibration factor from cell EEPROM reduces set-up time.
• Integral electronics with local HMI simplifies installation and shortens calibration times.
• Modular plug-in construction simplifies electrode replacements.
• Local display and keypad facilitates quick set-up, calibration, and operational activities.
• ½” NPT conduit connection provides increased protection and noise immunity of output cable
• Plug-in modular design allows sensor to be safely removed and replaced without cycling power on the electronics module.
• Electronics and sensor diagnostics reduces troubleshooting times.
• Trim value or 1-point solution calibration options accommodates individual calibration techniques and reduces calibration time.
• Temperature Sensor calibration options for more accurate measurements.
• Playing card-sized guide facilitates simple, correct, and consistent calibration and configuration.
• Watertight sensor connection for reliability in submersion applications.
• Global approvals including:
     – CE Mark for industrial applications
     – UL General Purpose
     – CSA General Purpose
     – IP66 Type 4x Enclosure
     – FM Class I, Div. 1 (I.S.) 
     – FM Class I, Div. 2 (non-incendive field wiring)

Display Ranges Conductivity: 0 to 2000 μS/cm, 0 to 20.00 mS/cm,
0 to 1000 mS/cm
Resistivity: 0 to 20.00 MΩ-cm
Total Dissolved Solids (TDS): 0 to 2000 ppm,
0 to 2000 ppb, 0 to 200ppt
% Concentration: 0 to 20.00%
Displayed Temperature Range –10 °C to +140 °C (14 °F to 284 °F)
Display Accuracy Conductivity/Resistivity: Greater of +/- 2 counts or +/-
0.5% of reading
Concentration: +/- 0.5% of reading
Temperature: +/- 0.1°C from –10 to 99.9°C, +/- 1°C from
100 to 140 °C
Display Resolution 4 digits, floating decimal point
Process Temperature –10 °C to +140 °C (14 °F to 284 °F)
Electronics Module Ambient Temperature –20 °C to +85 °C (–4 °F to +185 °F)
Output Type 4-20 mA (2-wire loop powered)
Output Calibration 4-20 mA
Cell Constant and Cell Calibration Factor Input Automatic from EEPROM in Conductivity Cell
Output (Loop) Cable Connection M12 Type
Output (Loop) User Termination Tinned leads on cord set or customer supplied cable
Cable Lengths Remote Sensor: 20 feet (cable integral to conductivity cell)
Output: 20 feet or 50 feet
Power 16-42 Vdc, 23mA max
Maximum load resistance:
250 ohms at 16 Vdc
600 ohms at 24 Vdc
1400 ohms at 42 Vdc
Local Display and Buttons LCD 4-digit, 7-segment
Engineering Units (Labels) μS/cm, mS/cm, MΩ-cm, ppm TDS, ppb TDS, ppt TDS, %
Calibration Options Cal Trim Factor, 1 Point Cal Solution
Solution Temperature Compensation Acid (Cation/Ammonia), Salt (Neutral Salts), NaCl, HCl, NaOH, H2SO4, and None (for USP24 Conformance)
Diagnostics Sensor and electronics
Case Weatherproof, corrosion-resistant plastic housing
Approvals CE Mark for Industrial Applications
UL – General Purpose for Process Control
CSA General Purpose for Process Control
FM Intrinsically Safe, Class I, Div. 1, Groups A, B, C, D
and Class I, Zone 0, AEx ia IIC
FM Class I, Div. 2, Groups A, B, C, D and Class I, Zone 2,
Groups IIC
Enclosure: Type 4x, IP66
Remote Mounting Pipe, Wall, or DIN Rail
Dimensions H 123 mm (4.84") x W 48 mm (1.89") x D 46 mm (1.81")
Weight Approximately 142 g (5.0 oz.)

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