Water Quality


HL7 Multi-Parameter Water Quality Meter

The HYDROLAB HL7 multiparameter sonde is a world class water quality meter suitable for spot check or unattended water quality monitoring.

Versatile and durable, the Hydrolab HL7 has a large sensor suite including:

Conductivity (EC)
Salinity (SAL)
Oxidation-Reduction Potential (ORP)
Dissolved Oxygen (LDO)
Chlorophyll a
Blue Green Algae
Total Dissolved Gas
• Phycoerythrin

When measured in real time, results can be viewed on the Hydrolab Surveyor handheld display:   Surveyor HL – Aqualab

Designed for water quality professionals, the Hydrolab HL7 is able to thrive in demanding environmental conditions.  Bio-fouling is minimized when equipped with the central cleaning brush and performance is maximized with an advanced power management system.

Various cable lengths are available with all Hydrolab HL7 models:

• 2 meter
• 5 meter
• 10 meter
• 15 meter
• 25 meter
• 25 meter
• 30 meter
• 50 meter
• 75 meter
• 100 meter
• 150 meter
• 200 meter

With the following output interface, the Hydrolab HL7 is able to easily integrate into real time telemetry systems:


• SDI-12
• RS-485
• RS-232


  • Quick and simple battery cartridge removable
  • Bail design aids instrument handling, transport and secure deployment options
  • Color coded status indicators to know the battery power source is working properly
  • USB for quick data transfer to rugged tablets and field laptop

Sensor Ports 9 sensor ports available
Dimensions Diameter: 8.9 cm (3.5 in.) without rubber bumpers; 9.8 cm (3.85 in.) with rubber bumpers
Length: 66.4 cm (26.1 in.)
Weights 4.5 kg (10 lb) with four Dcell batteries, storage/calibration cup with no liquid
Power Requirements 6…24 VDC (12 VDC nominal) applied to the communications module, 12 VDC:2.0 W average, 24 W peak
Battery Life* 90 days
Operating Temperature -5 to 50 °C (23 to 122 °F), nonfreezing
Storage Temperature 1 to 50 °C (34 to 122 °F)
Depth 200 m (656 ft) maximum
Data Memory 4 GB
Tensile strength (Maximum) Mooring cap: 68 kg (150 lb); deployment cable: 227 kg (500 lb)
Communications Communications module: USB, SDI12,RS232 Modbus, RS485 Modbus and RS232 TTY
Sampling Rate 1 Hz minimum, (once per second)
Hydrolab HL7 Brochure - AUS

Hydrolab HL7 Brochure - AUS

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Hydrolab HL7 User Manual

Hydrolab HL7 User Manual

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Additional files
Hydrolab HL7 Technical Data Sheet

Hydrolab HL7 Technical Data Sheet

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Optional Accessories
  • Hydrolab HL7 - Flow Cell
    Product number# 014120
  • Hydrolab HL7 - Calibration Stand
    Product number# 013910
  • Hydrolab HL7 - Weighted Sensor Guard
    Product number# 8457100
  • Hydrolab HL7 - LDO Sensor Cap
    Product number# 007460
  • Hydrolab HL7 - Storage Cup
    Product number# 003608
  • Hydrolab HL7 - Silicon Grease
    Product number# 000298HY
  • Hydrolab HL7 - 2m Cable
    Product number# CZL002
  • Hydrolab HL7 - 5m Cable
    Product number# CZL005
  • Hydrolab HL7 - 10m Cable
    Product number# CZL010
  • Hydrolab HL7 - 15m Cable
    Product number# CZL015
  • Hydrolab HL7 - 25m Cable
    Product number# CZL025
  • Hydrolab HL7 - 30m Cable
    Product number# CZL030
  • Hydrolab HL7 - 50m Cable
    Product number# CZL050
  • Hydrolab HL7 - 75m Cable
    Product number# CZL075
  • Hydrolab HL7 - 100m Cable
    Product number# CZL100
  • Hydrolab HL7 - 150m Cable
    Product number# CZL150
  • Hydrolab HL7 - 200m Cable
    Product number# CZL200
  • Hydrolab HL7 - Communications Cable (Lab use only)
    Product number# 9310600
  • Hydrolab HL7 Overview
  • Water Quality Monitoring with OTT HydroMet

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