Air Quality

Alphasense Product Guide

A product range specificallydesigned for Air Quality instruments
Our range of responsive gas and particulate sensors is supported by over 25 years of design and manufacture
experience, and our sensors are suitable for a range of different applications in fixed or portable detection
instruments. Every electrochemical sensor is performance tested and supplied with test data to aid calibration.

Electrochemical sensors
for PPB measurement

Optical Particle Counters (OPC)
for PM1, PM2.5, PM4.25, PM10

Photoionisation Detectors (PID)
for VOC measurement

Non Dispersive Infra Red (NDIR)
for CO2 and LEL/CH4

Air Quality applications
Indoor Air Quality

Growing awareness of the need to monitor and manage
Indoor Air Quality is driving significant advances in systems
and instrumentation. Alphasense Air Quality sensors areplaying a key role in this growth, specifically in industrial &commercial applications where users require meaningful
data (vs. any data) or where sensors are linked to control
systems for Air Quality management and ventilation.

Cleanroom

With airborne contaminants having a detrimental effect on
quality and yield, the production of high-tech components
such as semiconductors, PCBs and optics requires thehighest levels of cleanliness. Alphasense Air Quality
sensors, with PPB level detection and zero cross-sensitivity
to alcohol vapours, are well suited to cleanrooms. For
particle monitoring, Alphasense OPCs deliver best-in-classperformance at a price that allows for increased density ofmonitoring points.

HVAC

As HVAC systems become more sophisticated and the direct
impact of ventilation on wellness becomes more apparent,
Air Quality and particulate monitoring are increasingly being
integrated into HVAC systems. Alphasense sensors provide
OEMs with the opportunity to detect more than 20 specificgases including Carbon Dioxide, Carbon Monoxide andAmmonia, as well as both PID and electrochemical VOC
detection. The addition of Alphasense’s OPCs to HVAC systems
enable reference instrument level monitoring of PM1, PM2.5,
PM4.25 and PM10 at a fraction of the price, ensuring HVAC
systems enhance rather than endanger the lives they impact.

Dust monitoring

As our collective understanding of the risks associatedwith long-term dust exposure increases, the need forparticulate monitoring also increases, from both a corporate
responsibility and legislative perspective. Alphasense Optical
Particle Counters deliver real-time measurement andaccurate data comparable to devices costing much more,making high-accuracy particle counting (down to PM1) viable
in a range of applications where it has until now been absent.

Outdoor Air Quality

Accurately monitoring outdoor Air Quality is key formeasuring both the short and long-term effects ofpollution. The Alphasense range of electrochemical PPB
sensors is the go-to range for manufacturers of outdoor AirQuality monitoring instruments, delivering high-quality dataaround the globe. Additionally, and not to be confused withother ‘low-cost’ devices, the Alphasense OPC range provides
data comparable with that of reference instruments at afraction of the cost, making accurate particle monitoring
more viable in a variety of applications.

Industrial process

Whether it’s to optimise production, protect workers or
to ensure compliance with regulatory standards, manyindustrial processes now require gas monitoring down toPPB levels or dust monitoring down to PM1. Alphasense’s
range of PPM and PM sensors deliver industry leading
response times and reliable data which can be integrated
either directly onto customer hardware or via our range of
support circuits and accessories.

Electrochemical sensors
We supply high-quality Oxygen, CO2 and toxic gas sensors to many of the world’s leading OEMs for the design anddevelopment of Air Quality monitoring instruments. Our electrochemical sensors are available in two different size
formats to suit a range of diverse instruments and measure down to low PPB levels for Air Quality applications.

A4 Series

CO-A4 Carbon Monoxide

H2S-A4 Hydrogen Sulphide

NO-A4 Nitric Oxide

OX-A431 Ozone

SO2-A4 Sulphur Dioxide

VOC-A4 Volatile
Organic Compounds

CO-B4 Carbon Monoxide

H2S-B4 Hydrogen SulphideNO-B4 Nitric Oxide

OX-B431 Ozone

SO2-B4 Sulphur Dioxide

VOC-B4 Volatile
Organic Compounds

NO2-A43F
Nitrogen Dioxide

B4 Series

NO2-B43F
Nitrogen Dioxide

Non Dispersive Infra Red (NDIR)
Alphasense CO2 and Methane infrared sensors are supplied in the industry standard miniature (20mm diameter)
gas sensor housing. Patented optics give the best signal to noise ratio of any 20mm diameter NDIR and universal
linearisation constants allow easy implementation. The on-board temperature sensor allows for software
compensation, including ideal gas law correction.

IRM-AT

IRC-AT

IRC-A1

MethaneCarbon Dioxide

Carbon Dioxide

Optical Particle Counters (OPCs)
We have pioneered a range of Optical Particle Counters (OPCs) designed by aerosol scientists and engineered todeliver high-quality particle counts and sizing at affordable prices. The range has continuously evolved to offer
the best quality, low-cost devices on the market, leading to our current offering: the OPC-N3 and OPC-R2.

OPC-N3OPC-R2• Counts PM1, PM2.5 and PM10(PM4.25 as an option)• Counts PM1, PM2.5, PM10(PM4.25 as an option)• Measures from 0.35μm to 40μm
(including pollen detection)• Measures from 0.30μm to 12.4μm• Sorts into 24 software size bins

• Size = 72mm(l) x 25.5mm(h) x 21.5mm(w)• Sorts into 16 software size bins

• Size = 75mm(l) x 63.5mm(h) x 60mm(w)Photoionisation Detectors (PIDs)
PIDs can measure Volatile Organic Compounds (VOCs) to very low concentrations. Considered the gold standard
for VOC measurement, Alphasense PIDs are compact and low power, with recently improved electronics andlonger lamp life. An extended family of lamps now include better BTEX and chlorinated VOC detection.

PID-A1

PID-AYPID-AH• 0-4,000 ppm range• 0-20 ppm range• 0-40 ppm range• 100 ppb minimum
detection level• 1 ppb minimum
detection level• 1 ppb minimum
detection level

PID-ARPID-AG• 0-200 ppm range• 0-10,000 ppm range• 10 ppb minimum
detection level• 500 ppb minimum
detection level

Air Quality sensor support circuits
We offer support circuits for the new ranges of A4 and B4 four-electrode sensors, together with a 4-20mA
transmitter board for our NDIR CO2 infrared sensor. A range of gas hoods, mounting kits and cables are alsoavailable for use with Alphasense support circuits.

Individual Sensor Boards (ISBs)
Individual Sensor Boards (ISBs) have been built with lowest
noise for the new B4 family of sensors, designed where best
resolution at low PPB levels is required in permanent fixed sitenetworks. Requiring 3.5 to 6.4 VDC input, they provide bufferedvoltage output from both the working and auxiliary electrodes.
Boards are pre-configured when you order for the type ofsensor, with fixed zero and electronic gain. Each ISB supports
one B4 sensor and requires less than 1.5 mA power.

Analogue Front Ends (AFEs)
The Analogue Front End (AFE) family of circuits is designed
for use with the Alphasense A4 family of four-electrode gas
sensors where space is critical, such as with mobile Air Quality
monitors. Options include a 2-sensor AFE, 3-sensor AFE and3-sensor +PID AFE. All circuits include a low noise bandgap toprovide 200 mV bias voltage for NO sensors. Requiring from
3.5 to 6.4 VDC supply, the 3-sensor board for example only
needs 2 mA power.

NotesContact us
If you would like to enquire about our products or have an Air Quality project you’d like to discuss with us, please
get in touch via our website, by email or by phone. We look forward to working with you soon.

Alphasense
Sensor Technology House
300 Avenue West
Skyline 120
Great Notley, BraintreeEssex, CM77 7AA
United Kingdom

alphasense.com

sensors.alphasense@ametek.com+44 (0) 1376 556700