To be used with the HL4 and HL7 multiprobes only 

The Surveyor HL is the handheld display that connects to the Hydrolab HL4 & HL7 for attended monitoring applications and for completing other common tasks with the sonde in the field. It is rugged and compact with a color screen that is visible in direct sunlight and a keypad with pronounced buttons for system navigation.

The menu structure and functions are modeled after the Hydrolab Operating Software to make it easy to use and provide feedback about the system’s status and access to onboard metadata. The Surveyor HL is powered by a rechargeable lithium-ion battery that holds enough energy to power a Hydrolab HL4 for 10 continuous hours.

Surveyor HL Features: 

  • Fully IP67 enclosure with hand strap and rubberized case for optimal grip
  • Threaded connector to securely attach the sonde deployment cable
  • Color LCD 3.5 inch QVGA display visible in direct sunlight
  • Rechargeable lithium-ion battery that can power an HL4 for 10 continuous hours. 


  • The Surveyor HL is designed to operate with the HL4 multiprobe only. It is not compatible with any other multiprobes from HydrotTech or Hydrolab.  
  • The standard Surveyor 4A is also not compatible with the HL4 multiprobe. 
  • The HydroTech PC tablet NX10 is fully compatible with the HL4 multiprobes.


  • Graphical display:
    • Color, LCD 3.5" QVGA
    •  Transflective (readable in direct sunlight) 
  • Power supply:
    • Lithium-ion rechargeable
    • Battery life: up to 10 hours continuosly on (20 °C) 
  • IP-Rating: Handheld meter: IP67 
  • Buoyancy: Positively buoyant in water.
  • Dimensions
    • LxWxH:21.8cmx9.4cmx5.3cm (8.6 in. x 3.7 in. x 2.1 in.)
    • Weight: 0.68 kg (1.5 lbs) 
  • Operating temperature: –5 to 50 °C (23 to 122 °F) 

      ( See vidoes below ) 

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