Answers to your
Frequently Asked Questions
Find information and answers to those frequently asked questions about
our testing equipment and how to make the most of your data and results.
General FAQs
What types of air particle monitors do you offer?
We provide a range of continuously reading air particle monitors, all designed and manufactured in-house. Our monitors use diffraction technology to ensure accuracy and reliability across various environments.
Can your instruments be customized for specific applications?
Yes, our team of expert engineers can work with you to tailor our instruments to meet your specific requirements. Contact our technical support team to discuss your needs.
What support do you offer after purchasing your instruments?
We provide ongoing technical support to ensure you get the most out of your Turnkey instruments. Our dedicated team is available via phone or email to answer your questions, troubleshoot issues, and guide you through setup and usage.
Do you sell third-party testing equipment?
No, all our instruments and testing equipment are designed, developed, and manufactured in-house. This allows us to fully understand and support every aspect of our products, ensuring the highest quality and reliability.
Can we collect our data from AirQWeb, to use in our own software?
Yes, customers can collect their data from the central database with an easy-to-use web service. It takes some parameters as input and returns the data in JSON format. You will have to write a simple script at your end. There is a guide on how to do this here:
https://airqweb-content.s3.eu-west-2.amazonaws.com/userManuals/DataCollectorAPI.pdf
https://airqweb-content.s3.eu-west-2.amazonaws.com/userManuals/DataCollectorAPI.pdf
Is there a manual for AirQWeb?
Yes, there is a manual on AirQWeb’s own site, at:
https://www.airqweb.com/userManuals/AirQWeb.pdf
https://www.airqweb.com/userManuals/AirQWeb.pdf
Returning equipment to Turnkey Instruments for recalibration & service/repair from outside the UK
View post here.
How do I connect my brake tester to the MOT Testing System?
View post here.
Air Particle Monitor FAQs
What is the fastest response time of your instruments?
One second. Though typically they are used to indicate the average concentration over one to fifteen minute intervals.
How do you weigh dust using light?
We don’t, but the light scattering technique we use allows our instruments to be calibrated gravimetrically with sufficient accuracy...
What are the benefits of your instruments?
We believe our instruments provide the best and most cost-effective means of real-time particle monitoring...
Can your instruments be networked?
Yes. Numerous instruments can be linked together using fixed wiring, radio telemetry, phone modems, or internet connections...
What else do your instruments measure?
Besides particle concentration, they can also be used to measure wind speed and direction, gas sensors, sound meters, and traffic counting.
Why is your technique so special?
Because we measure individual particles by analysing their scattered light at angles where it is virtually independent of composition...
Did Turnkey develop it themselves?
Yes, we have over 20 years of in-house technical expertise in dust measurement using light scattering.
What type of size selective inlet do you use?
None. We size the particles electronically within the instrument, measuring PM1, PM2.5, PM10 and TSP mass fractions simultaneously.
What is the size range of particles your instruments measure?
From about 0.5 microns in diameter up to 20 microns in diameter...
Isn’t the loss of the sub-0.5 micron particles important?
No. These particles contribute very little to the PM10 mass concentration.
What about particles bigger than 20 microns?
They are only really significant very close to the dust source, and then only in the TSP or inhalable mass fractions.
What type of light source do you use?
A visible laser with a wavelength of 0.67 microns, deep red in colour.
Why a laser? Why not an LED?
Lasers can be focused to illuminate a very small volume — small enough to ensure only one particle is illuminated at once.
What effect does particle color have on response?
We only look at light close to the laser beam, minimizing the effect of color or absorption.
Are you measuring particle extinction?
Not strictly. We measure the diffracted component of scattered light, which is independent of composition.
Is there a simple relationship between particle size and mass?
No. We size one particle at a time and use a lookup table to calculate equivalent mass.
How can you isolate a single particle?
We use a very small illuminated sample volume and statistical techniques for higher concentrations.
Why do you use an inlet heater?
To avoid mist interference and for compatibility with TEOM readings. Readings drop by ~50% with the heater on.
Do your instruments use a pump?
Yes, they continuously draw air using a pump. This helps collect filter samples for calibration.
What type of filter is it?
Whatman GFA 25 mm circle, with optional mounted and pre-weighed versions.
Do the particles deposit inside the photometer?
No. We use a sheath of clean air around the sample to prevent this.
What sample air flow rate do you use?
Just 0.6 litres per minute.
Why is the flow so low?
Because our instruments analyse individual particles and don’t need a high flow for accurate results.
How do you calibrate the instrument?
Using a reference instrument calibrated against gravimetric samples. Secondary references are used for customer instruments.
How accurate are your instruments?
Calibrated within ±10% of our references. Inter-instrument agreement can be better than 1–2%.
Say Hello
How To Find Us
From M6 junction 19, take the A556 towards Chester and Northwich. Stay on the A556 (don’t follow signs into Northwich) for 5 miles until you reach a large roundabout.
Go straight on, then at the traffic lights (by Roberts Bakery) turn left into Gadbrook Park.
At the mini-roundabout, go straight on and follow the road around. We are the last building on the right.