Flow calibrator for ambient particulate matter air samplers
Alicat’s FP-25 is a weatherproof, battery-powered flow, pressure and temperature calibrator for particulate matter (PM) air samplers used primarily by environmental ambient air monitoring personnel at the national agency level and by sampler manufacturers looking to improve their test and validation efficiency. They are also used by industrial facilities to monitor the air around their perimeter so they can make sure they are in compliance with Environmental Audits. Nearly all end-user FP-25 usage is outdoors and in ambient weather conditions.
Air monitoring technicians use the FP-25 to audit accurately the volumetric flow (actual flow), mass flow (standardised flow), barometric pressure and temperature readings of ambient air samplers.
The FP-25 undergoes an advanced calibration process to ensure an individual linear mass flow calibration curve. An accuracy of 1% of reading (there is no element of the accuracy statement linked to full-scale) across a wide 200:1 turndown, e.g. a 25 LPM unit can measure down to 0.125 LPM.
Most applications require readings of volumetric flow, not mass, as the measurement of particulate pollution is relative to a given volume of air. Importantly, the pressure drop (0.1 psi @ 16.7 slpm) across the instrument is incredibly small and this, together with a correction of volumetric flow based upon barometric pressure, all but makes the instrument invisible to the process. In other words, the very presence of the calibration device does not impact upon the flow rate it is trying to measure.
Direct sunlight artificially elevates in-flow temperature readings, so the FP-25 uses a deep-set temperature sensor and aluminum body to get the most accurate air temperature readings within the flow path. Furthermore, there is an external temperature probe to correct the volumetric flow reading based upon ambient air temperature.
Air samplers must run year-round, so the FP-25 is accurate down to -30°C. To achieve this, the FP-25 undergoes an extensive temperature compensation process with the recorded responses at each temperature becoming part of the FP-25’s calibration.
Humid air has a different density and viscosity than dry air, and this can induce errors exceeding 5% of reading. The FP-25 has a live humidity sensor in the flow path to continuously read and correct for humidity.
Direct Mode allows the FP-25 to connect directly to the 1.25” downtube of an air sampler without inducing additional stress on the pump. This ensures more accurate readings and allows hands-free operation. The display rotates 90° when used this way.
A.The Bluetooth version (FP-25BT) adds an externally-mounted, positionable Bluetooth antenna
Bluetooth use requires an Android tablet or iOS mobile device and the free Alicat Connect mobile app. FB-25BT’s Bluetooth antenna provides sufficient signal strength to penetrate the Faraday cage of an air monitoring station. The FP-25 includes 3 custom fittings, all with NPT face seals to minimise leaks and eliminate Teflon tape issues. A carry-case accommodates the FP-25 together with any and all accessories connected, helping the technician to store it how they use it.
More often than not, at some time or another a technician will inadvertently drop the FP-25 and by sheer bad luck this is bound to be when they are up on the top of a roof. The design is incredibly robust and will withstand this accidental treatment. Alicat perform the roof top test in a video on the thier website.
The FP-25 has also been engineered to be weatherproof, as all connectors are IP67 (with plug or cable connected); with an overall instrument rating of IP64/65. For additional assurance, the FP-25 carries the Alicat Limited Lifetime Warranty
See the product video here
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