Seametrics CT2X Logger X-Series Integration Guide
Real-Time Water Quality Measurements
The Seametrics CT2X Logger is a conductivity and temperature sensor with built-in data logging. The sensor is compatible with NexSens X-Series data loggers using the SDI-12 communication protocol and sensor interface. A pre-defined script on NexSens X-Series data loggers is able to detect, log, and transmit all parameters available on the sensor. Parameter data is transmitted, in real-time, at a user-specified interval (e.g., 10 minutes) to the NexSens WQData LIVE Web Datacenter. There, data is stored on customizable dashboards with statistics and graphical interfaces for each parameter. Users can download and send data reports via Email, FTP, or an API. Below is information on the settings and wiring required to integrate these sensors with a NexSens X-Series data logger.
Figure 1: Seametrics CT2X integration with NexSens X-Series data loggers for real-time water quality measurements.
Compatible Models
Seametrics provides CT2X models that are available to measure from 5 to 300 PSI, or~11.5 to 700 feet of water, respectively. The model of the sensor does not affect the wiring or integration outlined below.
Figure 2: Seametrics CT2X Conductivity Logger
Sensor Integration
All default settings on the CT2X sensor will work with NexSens X-Series data loggers. Once the sensor is wired or connected properly, a pre-defined script on the data logger will automatically detect the sensor.
1. Wiring
In nearly all applications involving NexSens integration, a waterproof UW8 plug will be added to the sensor cable. However, in other applications, when the sensor cable requires protection, it may need a connection to a NexSens UW-FWP or an external junction box. Both options are vented, allowing for the sensor’s compensation for atmospheric pressure. The SDI-12 interface allows for an automatic barometric compensation in absolute units.
 Figure 3: NexSens UW-FWP J-pin out |  Figure 4: 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 Color | Signal |
| 2 | J2 | Black | Blue/Shield | Ground |
| 5 | J5 | Red | White | +12V |
| 6 | J6 | Brown | Brown | SDI-12 |
*NexSens UW-FWP Field Wireable Plug
**NexSens UW Plug to Flying Lead Cable
2. Automatic Sensor Detection
After wiring in the proper signal connections to an X-Series data logger, the sensor can be programmed onto the logger via automatic detection.
X-Series Logger Detection and Script Information
The X-Series data loggers include a pre-loaded CT2X script, which must be enabled before detection.
| X2 Script Number | Communication Protocol | Baud Rate | Power Type | Warmup Period (sec) | Measurement Command |
| 2010 | SDI-12 | 1200 | Switch | 5 | C |
Script Parameters
The X-series script retrieves pressure and temperature data from the sensor. From these measurements, the logger then calculates the overall water level based on a known conversion factor.
| Parameter | Units |
| Temperature | C |
| Linear Conductivity* | µS/cm |
| Non-linear Conductivity** | µS/cm |
| Pressure | PSI |
| Salinity | ppt |
| TDS | mg/L |
| Level | ft |
*Linear conductivity is compensated by changes in temperature (2.1% per °C).
**Non-linear conductivity is utilized in natural waters, such as groundwater, streams, and rivers, that have very low conductivity. Conductivity in these natural waters typically does not respond to temperature in a linear fashion.
3. Setting up WQData LIVE
Once an X-Series data logger has finished a new sensor detection, it will automatically push the sensor configuration to the WQData LIVE web data center. Follow the three articles below to create a WQData LIVE account and a project/site. Then add the data logger to the project using the included claim code.
- Create a WQData LIVE Account
- Create a Project on WQData LIVE
- Add a Data Logger to a Project on WQData LIVE
Real-Time System Application
Real-time water quality measurements from the Seametrics CT2X Loggers are useful in various environmental monitoring applications.
Applicable Systems
Discover applicable uses for the Seametrics CT2X Loggers.
- Groundwater Monitoring Systems
- Saltwater Intrusion Systems
- Source Water Monitoring Systems
- Wellfield Monitoring Systems
Water Quality Measurements
Learn more about water quality measurements on the NexSens Blog Page.
Sensor Manual
For additional information on the Seametrics CT2X Logger, please refer to the Seametrics CT2X Logger Manual.