Water Quality


HL4 Multi-Parameter Water Quality Meter

The HYDROLAB HL4 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:

• Temperature
• Conductivity (EC)
• Salinity (SAL)
• pH
• Oxidation-Reduction Potential (ORP)
• Dissolved Oxygen (LDO)
• Depth
• Turbidity
• Nitrate
• Chloride
• Chlorophyll a
• Blue Green Algae
• Rhodamine
• Ammonia
• Total Dissolved Gas

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 HL4 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 HL4 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 HL4 is able to easily integrate into real time telemetry systems:


• SDI-12
• RS-485
• RS-232

  • Self-monitoring system reports the status of the instrument, flags the data, and shows the user where the problem is with assistance on how to solve the issue
  • User-scheduled calibration and maintenance intervals indicate when they are due
  • Guided and semi-automated calibration routines lead the user through the calibration process
  • Calibration results are stored with date and time, calibration type, user identification, and user notes
  • Check Calibration process allows the user to verify calibration and store the results
  • Calibration reports contain information about previous calibrations and calibration checks
  • Sensor status is saved with every line of data and is contained in the log file
  • Dedicated communications modules allow easy integration with data loggers and telemetry systems
  • Compatible with the Surveyor HL – a fully IP67 handheld designed for field use with a full-color screen that is visible in direct sunlight

Sensors Temperature sensor and up to four additional sensors plus depth and ORP
External 6 … 30 VDC (12 VDC nominal) applied to the communications module,12 VDC: 250 mW average, 19 W peak
Internal (Optional) Internal alkaline D-cell battery, non-rechargeable.
Sleep mode at 12 V 20 mA
Communications Hydrolab communications modules: USB, SDI-12, RS232, RS485, or TTY
Memory 4 GB of internal memory; 1 second interval minimum
User Interface
PC Software Hydrolab Operating Software
Handheld (Optional) Hydrolab Surveyor HL
Sonde Depth Rating 200 m (656 ft)
Maximum Deployment Cable 200 m (656 ft)
Diameter w/o bumpers 4.4 cm (1.75 in.)
Diameter with bumbers 5.3 cm (2.1 in.)
Weight with internal battery pack (IBP) and storage/calibration cup 2.2 kg (5 lb)
Length – no IBP, standard sensor guard 51.4 cm (20.25 in.)
Length – no IBP, extended sensor guard 66.4 cm (26.125 in.)
Length – IBP and standard sensor guard 62.2cm (24.5 in.)
Length – IBP and extended sensor guard 77.8 cm (30.625 in.)
Environmental conditions
Operating temperature -5 … 50 °C (23 … 122 °F), non-freezing
Storage temperature 1 … 50 °C (34 … 122 °F)
Optional Accessories
  • Hydrolab HL4 - Flow Cell (normal)
    Product number# 014880
  • Hydrolab HL4 - Flow Cell (extended sensor)
    Product number# 013520HY
  • Hydrolab HL4 - LDO Sensor Cap
    Product number# 007460
  • Hydrolab HL4 - 2m Cable
    Product number# CZL002
  • Hydrolab HL4 - 5m Cable
    Product number# CZL005
  • Hydrolab HL4 - 10m Cable
    Product number# CZL010
  • Hydrolab HL4 - 15m Cable
    Product number# CZL015
  • Hydrolab HL4 - 25m Cable
    Product number# CZL025
  • Hydrolab HL4 - 30m Cable
    Product number# CZL030
  • Hydrolab HL4 - 50m Cable
    Product number# CZL050
  • Hydrolab HL4 - 75m Cable
    Product number# CZL075
  • Hydrolab HL4 - 100m Cable
    Product number# CZL100
  • Hydrolab HL4 - 150m Cable
    Product number# CZL150
  • Hydrolab HL4 - 200m Cable
    Product number# CZL200
  • Hydrolab HL4 - Communications Cable (Lab use only)
    Product number# 9310600
  • HL4
  • Water Quality Monitoring with OTT HydroMet
  • Hydrolab HL4 Webinar (2014)

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