Sensors and fluid measurement
Our Centre is carrying out world-leading research into the design, development and use of novel sensors and measurement techniques in collaboration with its commercial spin-out, Surrey Sensors Ltd. Our sensor systems are now being used in a wide range of sectors including Formula 1, motorsport, avionics, UAVs, healthcare, commercial agriculture and elite sport.
With more than 25 years of experience in managing one of the UK's most sophisticated wind tunnel facilities, our Centre has developed world-leading technology and expertise in flow measurement, instrumentation and experimental automation.
Now an area of advanced research in its own right, we have developed some of the world's most powerful flow measurement probes; these have been used on scientific aircraft, UAVs and high-altitude pseudo satellites, as well as in research wind tunnels around the world.
Our technology extends beyond wind-tunnel applications as well. We have developed what is believed to be the world's smallest thermal anemometry system which has already been used in aircraft and marine applications; an air quality sensor based on pulsed gas-plasma discharges for use in environmental monitoring; an "artificial whisker" so sensitive it can detect forces smaller than the weight of an eyelash, and a high-precision spirometer, developed in collaboration with medical researchers at the Chest Unit at King's College Hospital, offering new non-intrusive diagnostic capability for medical clinicians.
Listen to Dr David Birch speaking about his sneezometer device.
Below are a few examples of sensors we have developed in response to a particular customer need. All sensors can be supplied independently, or together with integrated transducer arrays and data acquisition/management systems.
Commercial versions are available through Surrey Sensors Ltd.
Manufactured from acrylic, low-cost probes such as the standard Pitot-static probe shown here, include a temperature-compensated differential pressure transducer system with an analogue-to-digital converter for low-noise communications. Direct-to-USB versions are also available. Typical applications include:
- Low-interference, high-bandwidth measurements
- Micro-UAV airspeed systems
- Custom/unconventional probe fabrication
- Large probe arrays.
Simultaneous sampling data acquisition system, streaming (via USB) at up to 62 kHz. 8 analogue inputs, 18-bit fully-differential with adjustable range up to +/- 10 V. Also includes 8 digital I/O channels, one output clock channel and one 12-bit analogue output. Hardware and software triggering capability. May also be upgraded for on-board power, storage and wireless communication for telemetry applications.
Our custom-made probes are designed for specific applications and requirements. These can be constructed from stainless steel (for durability and use in harsh environments) or plastic (for a lower cost solution), and using our high-resolution 3D printing capability, even highly complex, exotic probe configurations are possible.
PID bi-directional MOSFET motor controller with encoder feedback.
A custom-designed 19-hole vorticity probe, this probe provides local spatial velocity gradients and more precise flow angularity measurements than conventional five- and seven-hole probes. Typical applications include:
- Measurement of swirling flows
- Velocity measurements requiring very high accuracy
- Measurements requiring very high reliability or robustness.
This constant current anemometer design uses a two-stage gain and two-stage active filter and buffer. Ultra-low noise levels are achieved through active cable compensation and shielding. A small-footprint surface-mount version is also available.
This directional velocity probe system offers unparalleled functionality in a highly compact, minimally intrusive package. This probe is undergoing certification for use on aircraft, but may equally be used in wind tunnel measurement or motorsport track testing. Features include:
- Seven-plus-one hole probe for velocity measurement, referenced to true local static pressure
- Seven-channel, temperature-compensated differential pressure transducer array
- Absolute static pressure and local air temperature sensors for high-accuracy data reduction
- Inertial positioning sensor for automated probe alignment
- Humidity sensor for density correction and condensation warning
- 16 bit, 1000 Hz data acquisition, streaming via RS-485
- Integrated sting and case heaters for de-icing
- Compact, in-line sensor package: 28 mm diameter, 80 mm long
- Solid stainless steel construction
- Sting diameters down to 3 mm OD available.
Manufactured from stainless steel, these micro-miniature conventional seven-hole probes have an outer diameter of 1.8 mm and a 45˚ conical tip. The probe shown here is pictured next to the head of a pin. Typical applications include:
- Measurement of highly sheared flows
- Measurement of sensitive flows
- Measurement in small facilities or of small models.
These miniature single-sensor hot-wire probes feature a sting and prongs of stainless steel, with epoxy filler, and are designed for low-interference intrusive flow measurements. Typical applications include:
- Measurement of fine-scale turbulence
- Model-integrated stings
- Measurement in small models.
Compact, modular array of up to 64 pressure transducers. Transducers are installed in 8-element units, and each unit may have a different full-scale range; this modularity provides maximum flexibility in the application. Transducer units are self-detecting and factory-calibrated, allowing the user to easily swap elements while in use. Features include:
- Array of 8, 16, 24, 32, 40, 48, 56 or 64 transducers, either differential or absolute
- Full-scale sensor ranges down to 250 Pa
- Local temperature and absolute (atmospheric) pressure sensors included, for maximum accuracy
- Humidity sensor for density correction and condensation warning
- Remote fluid temperature sensor also included, for local state estimation
- IMU for orientation and vibration detection
- External trigger input
- 16 bit, 1000 Hz data acquisition, streaming via USB
- USB powered - no additional external power supply required
- Supplied either as OEM unit (pictured) or with protective enclosure.
We can produce probes with complex geometries such as this new 37-hole, 12mm diameter omnidirectional velocity probe, using high-resolution rapid prototyping techniques. Together with our low-cost, small-size transducer arrays, these probes offer excellent range and precision, even functioning in regions of reversed flow. Typical applications include:
- High-precision air data systems
- Meteorological monitoring stations
- Measurement of mixing/swirling flows.
What we can offer you
We are unique in being able to prototype sensor systems in any configuration, using techniques including 3D printing, within a short turnaround time. We can also produce low cost, miniature constant-temperature and constant-current anemometer systems for turbulence and temperature measurements.
Take a look a look at the offering listed on our Surrey Sensors Ltd site.
We are developing our fluid sensing systems for clinical research and medical diagnostics with the Centre for Biomedical Engineering here at Surrey.
If you have any queries or are interested in us solving a problem for you then please contact our research lead.