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DH4 Sensor Interface Module

DH4 is a sensor for the collection, storage, and merging of digital and analog data from up to eight sensors.


  • Complex sensor integration and data logging.
  • Simultaneous collection, storage, and merging of data from up to eight serial output sensors or seven analog output sensors in both profile and moored modes.
  • Data from any of the sensors may be viewed in real-time through its own host software while data is being collected and stored for others.
  • Supports a variety of serial-interface (RS-232) sensors as well as voltage-output (0 - 5 V) sensors.
  • Window-based software that provides DH4 configuration, control, data downloading, and data processing.


  • A total of 4, 6, or 8 channels, in user-specified combination of serial interface and/or voltage input (up to 7 channels of voltage input can be provided).


Number of ports 4, 6, 8
Serial input RS-232
Analog input 0 - 5 V
Analog input resolution 12-bit A/D
Baud rates 600 - 115.2K
Data transfer Binary
Memory 1 GB


Diameter 10.4 cm
Length 17.8 cm
Weight in air 1.8 kg
Weight in water 0.3 kg
Pressure housing Acetal copolymer


Input 7-18 VDC
Current draw 50 mA
Sleep 70 µAmp (maximum)
Maximum total power 3 A at input voltage
Maximum power per port 2 A at input voltage
Sample rate 6 scans/sec, nominal
Host interfaces RS-232


Temperature range 0-30 deg C
Rated depth 500 m


The list below includes (as applicable) the current product brochure, manual, and quick guide; software manual(s); and application notes.

Title Type Publication Date PDF File
DH4 Datasheet Product Datasheet Tuesday, July 4, 2017 datasheet-dh4.pdf
DH4 Drawing Product Drawing Tuesday, July 4, 2017 drawing-DH4.pdf
DH4 Manual Product Manual Tuesday, July 4, 2017 manual-dh4.pdf
Version released July 5, 2017
DH4Hostv709e.exe for Windows 7/8/10

Version released July 5, 2017
wap437.exe for Windows 7/8/10

What should I use to lubricate bulkhead connectors?

WET Labs recommends keeping the connectors on your meter lubricated using a good quality silicone spray lubricant, such as 3M Silicone Spray or Loctite 8021 spray. These can be purchased at your local hardware store. Avoid silicone grease. It is messy and attracts contaminants.

Do not use WD-40. It will destroy connectors.

What is the input voltage range for my instrument?