AQUAlogger® 520

Temperature, pressure – to 1000m

Ideal for long-term deployments, temperature distribution surveys, oceanographic studies and environmental impact assessments.

The cost-effective solution for measuring temperature and depth underwater…

…giving accurate and reliable results in all water environments.

The AQUAlogger® 520 is a miniature instrument, capable of monitoring accurate temperature and pressure measurements at depths of up to 1000m. The device is a flexible alternative to thermistor chains, given its self-contained design. The AQUAlogger® 520 is an appropriate instrument for both ocean and environmental applications.


  • Long term deployments
  • Temperature distribution surveys
  • Flexible alternative to thermistor chains
  • Environmental impact assessments
  • Time series of temperature at fixed depths/points

Convenient design

  • The self-contained and compact design means the AQUAlogger 520 gives operators greater flexibility in deployment.
  • The instrument has a narrow diameter (just 32mm), which makes it suitable for taking accurate measurements in small spaces.
  • The AQUAlogger 520 has a USB-connected reader, which allows for easy uploading of up to 250,000 logged parameter readings, using a wireless communication system.
  • Since the AQUAlogger 520 does not require any connectors, you can be confident your data is protected against leaks.

Long-term deployment

  • The AQUAlogger 520 has a battery life of up to 5 years for a typical deployment setup.
  • With an expansive memory that can store up to 250,000 parameter readings and its low power technology, this low maintenance device will save you time and money in the field.

Reliable sensing

  • Each logger is individually calibrated by our expert team.
  • Aquatec offer an annual service and calibration plan, to ensure continuity of reliable data.
  • The logger can be supplied with pressure and temperature sensors, or temperature only, to enhance your understanding of the environment.

Ready to use

  • We supply you with everything you need to get started, including a reader, software and manuals.
  • The AQUAlogger is a cost-effective solution when purchasing many of the same instrument, as you will only need one reader to communicate with all of your loggers.

Sensor specification




Sensor type


Piezo-resistive bridge


-2 to 35°C standard, other ranges on request

2 bar (~10m), 4 bar (~30m), 5 bar (~40m), 11 bar (~100m), 51 bar (~500m), 101 bar (~1000m)
(Other sensors available on request)


better than 0.007°C

better than 0.01% full scale



typically better than 0.2% full scale

Time constant

better than 5 seconds to 63% of the change in value*


*High speed temperature probe with 1 second time constant also available.

Logger specification

Data storage capacity

> 250,000 parameter readings, in non-volatile FLASH

Option available for >500,000 parameter readings

Logging lifetime

Typically 5 years, depending on regime

Data retention

>10 years

Burst sampling

Bursts every 1 – 255 seconds or 1 – 255 minutes

Within-burst rate

From 1 Hz to once every 30 seconds

Burst averaging

Bursts may be averaged to a single data value

Logger communication

Wireless system via separate drop-in reader

Reader communication

USB 1.1, bus powered


3.6V Custom Lithium ‘AA’ cell - Technician replaceable


AQUAtalk for Windows for configuration and download


Single point attachment through mounting hole or use clamp

Maximum depth

1000 m


200mm (7.9”) long x 32mm (1.3”) diameter


190g (6.4oz) in air; 41g (1.5oz) in water

Q: I need to know the depth in metres.

A: A conversion from pressure to depth is now standard for AQUAlogger® 520 instruments.

Q: Does it fit into bore holes?

A: AQUAlogger® 520 has a diameter of 32mm, so should be suitable for deployment in boreholes.

Q: Can it provide the data in real time?

A: The AQUAlogger® 520 is a logging device and cannot provide information in real time. The AQUAlogger® 310PT has real time capability as standard.

Q: The battery lasts a long time but I need it to store more data.

A: A memory upgrade from 500kB to 1MB is available for the instrument.

Q: Can we replace the batteries ourselves?

A: The batteries are technician replaceable. We can supply spare batteries if required. Please note, your warranty will be void for leaks if the instrument is opened. A battery change is offered as standard in an annual service.