Seametrics PT12 Level Sensor X-Series Integration Guide

Real-Time Water Level Measurements

The Seametrics PT12 level sensor measures accurate pressure and temperature readings in nearly all environments. 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.

Seametrics PT12 Submersible Pressure Sensors product page.

Figure 1: Seametrics PT12 integration with NexSens X-Series data loggers for real-time water level measurements.




Compatible Models

Seametrics provides PT12 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.


Seametrics PT12 Level Sensor product page

Figure 2: Seametrics PT12 Level Sensor




Sensor Integration

All default settings on the PT12 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 ColorSignal

*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 PT12 script, which must be enabled before detection.

Configure Sensor Scripts

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


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.



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.



Real-Time System Application

Real-time water level measurements from Seametrics PT-12 Level Sensors are useful in various environmental monitoring applications.

Applicable Systems

Water level measurements from the Seametrics PT12 Level Sensor are useful in various environmental monitoring applications.


Case Studies

Read about specific applications using Seametrics PT12 Level Sensors.


Water Level Measurements

Learn more about water level measurements on the NexSens Blog Page.


Sensor Manual

For additional information on the Seametrics PT12 Level Sensor, please refer to the PT12 Pressure Sensor Manual.