Seametrics CT2X Logger X2 Integration Guide

The Seametrics CT2X is a conductivity and temperature sensor with built-in data logging. The sensor is compatible with the X2 data logger using the SDI-12 communication protocol and sensor interface. NexSens can install a waterproof connector, or the user can wire the sensor into a NexSens UW-FWP or external junction box for connection with an X2. Below is the wiring information for the sensor and information on the pre-defined SDI-12 script for the CT2X.

Seametrics CT2X Conductivity and Temperature sensor product page

Figure 1: Seametrics CT2X Conductivity Logger



In nearly all applications involving NexSens integration, a waterproof UW8 plug will be added to the sensor cable. However, other applications may require connection to a NexSens UW-FWP or an external junction box. The following table provides information for both applications.

Figure 2: NexSens UW-FWP J-pin out

Figure 3: NexSens UW8/UW-FWP Plug pin out


NexSens UW8/
UW-FWP Plug Pin
UW-FWP J Pin*NexSens UW8-FLx Wire Color**Seametrics PT12 Wire ColorSignal

*NexSens UW-FWP Field Wireable Plug
**NexSens UW Plug to Flying Lead Cable


X2 Script Information

The X2 data logger includes a pre-loaded Seametrics CT2X Conductivity and Temperature sensor (SDI-12) script. Use the CONNECT software to enable the script for sensor detection.

Configure Sensor Scripts

X2 Script NumberCommunication ProtocolBaud RatePower TypeWarmup Period (sec)Measurement Command


Script Parameters

The X2 script retrieves pressure and temperature data from the sensor. From these measurements, the X2 then calculates the overall water level based on a known conversion.

Linear Conductivity*µS/cm
Non-linear Conductivity**µS/cm

*Linear conductivity is compensated by changes in temperature (2.1% per °C).
**Non-linear conductivity is utilized in natural waters, such as ground water, streams, and rivers, that have very low conductivity. Conductivity in these natural waters typically do not respond to temperature in a linear fashion.


Conductivity Measurements

Learn more about conductivity measurements in the Fondriest Environmental Learning Center.


Applicable Systems

Conductivity and temperature measurements from the Seametrics CT2X Logger are useful in various environmental monitoring applications.