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 ports4, 6, 8
Serial inputRS-232
Analog input0 - 5 V
Analog input resolution12-bit A/D
Baud rates600 - 115.2K
Data transferBinary
Memory1 GB


Diameter10.4 cm
Length17.8 cm
Weight in air1.8 kg
Weight in water0.3 kg
Pressure housingAcetal copolymer


Input7-18 VDC
Current draw50 mA
Sleep70 µAmp (maximum)
Maximum total power3 A at input voltage
Maximum power per port2 A at input voltage
Sample rate6 scans/sec, nominal
Host interfacesRS-232


Temperature range0-30 deg C
Rated depth500 m
Specifications are subject to change without notice.


Download DH4 Host 7.09e

Released April 16, 2013
WLHostv709e.exe for Windows XP/Vista/7

WAP can process data streams from multiple sensors.

Released March 3, 2015
wap437.exe for Windows XP/Vista/7
Product Datasheet

DH4 Datasheet

Wednesday, November 4, 2015

DH4 Product Drawing

Thursday, November 5, 2015
Product Manual

DH4 Manual

Monday, December 28, 2015
Product Manual

WAP User's Guide

Thursday, June 27, 2013
Technical Note

Cable and Bulkhead Connector Maintenance

Thursday, March 9, 2017
Technical Note

Instrument Voltage Ranges (in VDC)

Thursday, June 21, 2012

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.