Company Profile

Air Flow Measurement Instruments and Air Flow Measurement Devices for HVAC Tech Field Kits

Quick Answer: HVAC field teams need air flow measurement devices that are easy to carry, simple to connect, and stable in dusty or humid ducts. Silver Automation Instruments supplies insertion thermal mass flow meters for duct air and inline thermal mass flow meters for compressed air. Send your duct size, velocity range, and temperature to get a specific model recommendation.

HVAC technicians often start with hot wire anemometers and pitot tubes for field checks. These tools are fine for spot measurements. But when a building automation system needs permanent airflow data, a thermal mass flow meter from Silver Instruments gives you a 4-20 mA HART signal and a local display. The probe fits into a DN50 to DN300 duct without cutting the pipe.

Why HVAC Field Kits Need Rugged Air Flow Measurement Instruments

Most HVAC air flow meters fail because they are not built for real duct conditions. We have seen this on customer sites many times in Southeast Asia. Humidity in Malaysia and Thailand can reach 90 percent. Standard hot wire sensors drift after a few weeks. Silver Instruments uses stainless steel probes and IP65 housings. The sensor element is protected from dust and condensation.

Here is the thing. A portable device with a short probe works for hood exhaust checks. But a fixed insertion probe gives continuous total airflow. You do not need to drill multiple holes in old ducts. One insertion point works if the straight run is long enough. For round ducts below DN300, use the inline thermal mass meter with threaded or flanged connections.

Key Parameters for HVAC Air Flow Devices

We ask engineers for four values before quoting. First, the pipe or duct inner diameter in DN. Second, the normal and maximum air velocity in Nm/s or m/s. Third, the air temperature in degrees Celsius. Fourth, the output signal and power supply. Typical HVAC sites use 24 VDC and a 4-20 mA HART signal to the BMS or PLC.

Silver Instruments thermal mass air flow meters cover 0.3 to 100 Nm/s. Accuracy is plus or minus 1.5 percent of reading from 20 to 100 percent of range. Duct air temperature can range from minus 40 to 150 Celsius. Pressure rating is 16 bar for inline compressed air meters. Insertion probes are rated for low pressure ducts up to 2 bar. Process connection options include G1/2 inch, 3/4 inch NPT, and DN25 flange.

Typical HVAC Applications We Support

Last year a customer in Vietnam asked us for a compressed air leak audit at an electronics assembly plant. They installed three inline thermal mass flow meters on DN25 and DN40 compressed air headers. The meters send RS485 Modbus RTU data to a paperless recorder. The plant now finds pressure drops before they affect pick and place machines.

A facilities contractor in Australia uses our insertion thermal mass probe to verify fresh air intake in commercial kitchens. The probe inserts into a DN250 duct and shows normal cubic meters per hour on a local display. Because the output is 4-20 mA HART, the building management system logs the outdoor air ratio automatically. No handheld anemometer is needed for weekly checks.

In the Middle East, district cooling plants measure cooling tower air intake with our IP65 insertion probes. Sand and dust are common. The stainless steel probe and no moving parts design survive longer than vane anemometers.

Recommended Field Kit Setup

A practical HVAC field kit from Silver Instruments can include one insertion thermal mass flow meter, one inline thermal mass flow meter for compressed air, a 24 VDC power supply, and a handheld display with Modbus readback. This covers duct air velocity and compressed air mass flow in the same service van. Technicians can keep the insertion probe in a hard case and mount the inline meter permanently on critical air lines.