A Dirty probe can refer to two main things a dirty air pitot probe used for measuring airflow in dirty environments, or a contaminated medical probe that needs proper cleaning and disinfection. The term can also describe a fouled conductivity probe, which needs to be cleaned to ensure accurate readings.

A Dirty Probe is a specialised flow-measurement instrument designed to operate in dust-laden, particulate-rich and contaminated gas or air streams where standard Pitot tubes cannot function reliably. These probes are commonly used in industrial stacks, chimneys, boilers, exhaust ducts and emission-monitoring systems. Their construction allows them to measure velocity pressure even in harsh environments containing ash, soot, unburnt particles or corrosive fumes.

The probe’s robust design minimises clogging and ensures stable readings during continuous operation. Dirty probes are widely used in pollution-control monitoring, process-plant efficiency studies and flue-gas analysis. They help industries obtain dependable velocity measurements for regulatory reporting, system balancing and performance evaluation, even under challenging operating conditions.

Key Features & Advantages

• Suitable for dust-laden and particulate-rich gas streams

• Larger pressure ports to prevent frequent clogging

• Compatible with differential pressure instruments (manometers, sensors)

• High-temperature and corrosion-resistant construction

• Designed for industrial stack testing and emission measurement

• Stable performance in non-ideal, turbulent flow conditions