TFPITOT01 - Lightweight Pitot Tube with Integrated Differential Pressure Sensor

TFPITOT01 side view

The TFPITOT01 is an ultra-lightweight pitot tube that integrates the SDP33 sensor, providing a compact and reliable airspeed measurement solution. This design eliminates common issues associated with traditional low-cost pitot tubes, including temperature drift, offset, and the failure of tubing systems.

Key Features

  • Compact Design – Eliminates external tubing, reducing weight and enhancing reliability.
  • Stable Measurements – No temperature drift or offset, ensuring high accuracy in various conditions.
  • High Moisture Resistance – Designed to handle condensation and humidity, maintaining performance in challenging environments.
  • PX4 & Ardupilot Compatibility – Seamless integration with popular flight control software for UAV applications.

Technical Specifications

  • Sensor Type: Sensirion SDP33
  • Measurement Range: ±1500 Pa (1 m/s to 50 m/s)
  • Accuracy: ±3% of measured value (corresponds to ±1.5 m/s @ 50 m/s)
  • Zero Point Accuracy: 0.2 Pa
  • Operating Temperature Range: -40 °C to +85 °C
  • Dimensions: 45 mm length, 6 mm diameter
  • Weight: 3 grams
  • Default I2C Address: 0x21 (configurable to 0x22 or 0x23)

Applications

The TFPITOT01 is designed for use in Unmanned Aerial Vehicles (UAVs), providing precise airspeed measurements for atmospheric monitoring, navigation, and performance optimization.

Installation Guide

Mounting Instructions

To ensure reliable airspeed measurements, the pitot tube must be installed correctly:

  1. The tube must be parallel to the airflow to guarantee accurate readings.
  2. Mounting possibilities:
    • Clamp Mounting: Use a dedicated bracket or clamp to secure the tube.
    • Adhesive Bonding: Bond the tube into a pre-fabricated socket or flange on the fuselage or wing structure.
  3. Ensure that the electronic components and I2C cable are sealed against moisture. Only the intake holes at the front of the pitot tube should be exposed to airflow.

The preferred orientation of the mounted sensor is PCB to up. This position ensures that ingressed water can flow out or evaporate. This mounting is especially useful in situations of mounting in the wing. Where the sensor should be screwed from the bottom of the wing.

Electrical Connection

  • Connect the TFPITOT01 to an unused I2C port on the flight controller.
  • Configure the firmware settings to recognize the sdp3x sensor driver for airspeed measurements.

Calibration

Follow the calibration procedure as outlined in the documentation for your flight control firmware (PX4/Ardupilot) to achieve optimal accuracy.

Availability and Customization

The TFPITOT01 is available from ThunderFly s.r.o..

  • For commercial inquiries, contact sale@thunderfly.cz.
  • Orders can be placed via our Tindie store.
  • Customization options, including length or diameter modifications, are available upon request (typical lead time: 3 weeks).

FAQ: Frequently Asked Questions

Can a pitot probe be used on a quadcopter?

Yes, a pitot probe can measure airspeed on a quadcopter as long as it is facing the relative airflow. In the case where the UAV always flies forward in a specific direction, the pitot tube will register dynamic pressure corresponding to the component of airspeed aligned with its axis.

How does the quadcopter’s pitch angle affect pitot tube measurements?

A pitot probe only measures the airspeed component along its own axis. If the quadcopter changes its pitch angle during flight, the probe may not capture the full airspeed but rather its projection onto the probe’s axis. This can lead to underestimation of actual airspeed unless compensated.

How can I correct for pitch angle effects?

There are two common approaches:

  1. Using the known attitude – By integrating pitch angle data from an IMU, you can adjust the pitot tube reading to estimate true airspeed.
  2. Using a multi-port airspeed sensor – The multiple probes or a 5-hole TFPITOT probe can measure both airspeed and roughtly angle of attack, providing more accurate velocity data.

What airspeed range can a pitot tube measure on a quadcopter?

A pitot probe can generally measure airspeeds starting from a few meters per second. For a flight speed under 10 m/s, the TFSLOT01 sensor is recommended for better accuracy.

Where should the pitot tube be mounted on an airframe?

For best results, the probe should be placed:

  • In clean airflow, away from propeller wash and frame turbulence.
  • With the tip facing directly into the relative wind to ensure accurate measurements.
  • Ideally on a boom or mast extending forward to minimize aerodynamic disturbances.