In-Situ Troll® 9500 Multiparameter Instrument

The powerful, portable TROLL 9500 Water Quality Instrument is designed for groundwater and surface water monitoring. The unit houses up to nine water quality sensors, internal power, and optional data logger.

Lower Total Cost of Ownership

  • Instrument saves time and money by offering long-lasting internal power, automated low-flow sampling, and telemetry accessibility.
  • Field-proven sensors and antifouling system reduce maintenance and site visits.
  • Intuitive Win-Situ® 4 Software and Flow-Sense Software improve efficiency by simplifying data collection and management.

Reliable, Accurate Operation

  • Instrument operates in fresh, waste, and marine waters.
  • Instrument offers proven performance. Rigorous third-party testing shows that the TROLL 9500 delivers consistent results.
  • Sensors are factory calibrated with NIST®-traceable standards (where applicable).

Outstanding Customer Service

  • Free manufacturer 24/7 technical support
  • In-Situ 1-800-446-7488

Logging Models

  • LTS: LTS stands for "Level, Temperature, and one additional Sensor," such as conductivity, dissolved oxygen (DO), or pH.
  • Professional: This unit offers the highest value for most applications. Instrument allows for several sensors, including conductivity/salinity, DO, ORP, pH, temperature, or depth.
  • Professional XP: The most capable TROLL 9500 offers features available on the Professional and supports XP or "Extended Parameter" sensors–turbidity, ammonium, chloride, or nitrate.

Non-Logging Models

  • Profiler: Ideal for sampling or vertical profiling, this unit is similar to the Professional, but does not include memory or logging capabilities. Data can be logged to a RuggedReader® Handheld PC or laptop.
  • Profiler XP: This unit offers the same features as the Profiler with the option to use XP sensors.

Close block


  • Coastal deployments – estuaries and wetlands
  • Environmental monitoring and spot checking
  • Low-flow groundwater sampling
  • Remediation and mine water monitoring
  • Stormwater management
  • Vertical profiling

Please Note: Water Quality Product Update

The latest and greatest in water quality monitoring is here...which means we're making some changes.

Over the last decade, the TROLL 9500 Multiparameter Sonde has been In-Situ's primary water quality instrument, and has served well in a variety of applications. With new advancements in technology, we saw a need to provide a new water quality platform with increased functionality and performance and, as a result, we are proud to offer the new Aqua TROLL 600 Multiparameter Sonde.

With the release of the Aqua TROLL 600, we have decided to cease production of the TROLL 9500 Multiparameter Sonde in the coming months.

If you currently own a TROLL 9500, rest assured - we will offer phone support, service and replacement parts for the next three years*.


Q: How long is service for the TROLL 9500 going to be supported?

A: We will offer instrument evaluation, sensor calibration and service/repair for the next three years.*

Q: What replacement parts will be available, and will they be new or remanufactured?

A: We will offer replacement parts for the next three years. Replacement parts will be new unless otherwise specified on your return order.*

Q: What advantages does the Aqua TROLL 600 have over the TROLL 9500?

A: The Aqua TROLL 600 features the latest advancements in state-of-the-art water quality monitoring technology. It offers a 9+ month battery life, universal sensor ports and wet-mateable connectors, a suite of digital smart sensors, and internal memory plus an onboard SD card for backup storage. It is the only multiparameter sonde to have a sub-2 inch passive and active antifouling system for all sensors, including conductivity, by featuring an integrated dual-sided wiper and flat-faced sensor design. These are just some of the features that set the Aqua TROLL 600 apart from the rest.

*We plan to have parts available for 3 years, but this may be longer or shorter depending on actual consumption.