# Temperature and Pressure Sensors

## Hardware Installation

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Using a T10 Torx screwdriver, slightly loosen all screws on the back plate of the Surveyor 240 housing. Once all screws have been loosened, remove the screws and carefully lift off the back plate.&#x20;

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Locate the four mounting screws securing the Surveyor 240 circuit board. Using a 2.5mm hex screwdriver, remove these screws. Gently lift the Surveyor 240 board straight up and out of the housing.&#x20;

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Using two 16mm wrenches, unscrew the blank penetrator and retaining nut from the housing. Apply grease (e.g., Molykote) to the o-ring on the sensor. Insert the sensor into the port previously occupied by the blank penetrator and hand-tighten the retaining nut. Then, using the 16mm wrenches, securely tighten the pressure sensor and nut to ensure the sensor is firmly seated.

Plug the sensor into the port on the Surveyor 240 board labeled Depth Sensor.

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With the sensor installed and the board in place, reattach the Surveyor 240 board to the board beneath it, and then to the posts using the four screws. Ensure that the large o-ring is seated in the groove of the main housing, then reinstall the back plate and tighten all screws with the T10 Torx screwdriver in a star pattern until each screw is hand tight.

## Reading Sensor Data

### Bar30 Depth/Pressure Sensor

Pressure and temperature data from the Bar30 sensor are transmitted in the Surveyor 240's [WATER\_STATS](https://docs.ceruleansonar.com/c/surveyor-240-16/application-programming-interface/water_stats) and [YZ\_POINT\_DATA](https://docs.ceruleansonar.com/c/surveyor-240-16/application-programming-interface/yz_point_data) packets. Both packet payloads contain:

* **temperature**: reported in degrees Celsius
* **pressure**: reported in Bar

### Celsius Temperature Sensor

Temperature data from the Celsius Temperature Sensor is transmitted in the Surveyor 240's [WATER\_STATS](https://docs.ceruleansonar.com/c/surveyor-240-16/application-programming-interface/water_stats) and [YZ\_POINT\_DATA](https://docs.ceruleansonar.com/c/surveyor-240-16/application-programming-interface/yz_point_data) packets. Both packet payloads contain:

* **temperature**: reported in degrees Celsius
* **pressure:** will report -1000 Bar (indicating no pressure data available)