Industrial Compressed Air Leak and Pressure Monitor with Dashboard

Compressed air is one of the costliest utilities in a workshop, and a large share of it hisses out of leaking joints, worn couplings and valves left open — invisible, continuous waste. Energy audits estimate leaks with a one-time ultrasonic survey; nobody watches the system day to day. The engineering gap is continuous monitoring: line pressure on a live curve, leak rate estimated from how fast pressure decays when the plant is idle, and compressor duty cycle logged so the cost of the leaks shows up as kilowatt-hours. This project builds that on an ESP32: a pressure transducer on the ring main, a solenoid valve the firmware uses for controlled decay tests, and a dashboard with pressure curves, leak-rate trend and duty analytics.

1. The pressure transducer on the ring main feeds the ESP32 a continuous pressure reading.
2. Firmware logs pressure, marks compressor cut-in/cut-out transitions, and accumulates duty cycle per shift.
3. During a scheduled off-hours window (or on demand from the dashboard), the controller runs a decay test: with no plant demand, it records pressure fall over a fixed time.
4. The decay slope converts to an estimated leak rate using the receiver volume — documented honestly as an estimate, not a metered flow.
5. Sudden daytime dips are classified as demand spikes and logged separately from the leak baseline.
6. Everything streams to the dashboard: live pressure, leak-rate trend over weeks, duty per shift and the event feed.

Tech stack:

• ESP32 development board (Wi-Fi telemetry)
• Pressure transducer (4–20 mA / 0–5 V type)
• Solenoid valve (drain + decay-test isolation)
• Air receiver tank + reference pressure gauge (demo rig)
• Relay module (compressor/valve interface)
• Single-page plant dashboard (HTML/JS)
• Arduino IDE (C/C++ firmware)

• [Live pressure telemetry] The transducer streams ring-main pressure to the dashboard on a continuous curve, with cut-in/cut-out events marked.
• [Leak-rate estimation] Off-hours decay tests measure how fast pressure falls with no demand; firmware converts the decay to an estimated leak rate in L/min.
• [Compressor duty logging] Loaded versus total run time is logged per shift, so rising duty at constant production points at growing leaks.
• [Demand-spike flagging] Sudden pressure dips with the compressor running are flagged as demand events versus leak signatures.
• [Auto drain control] The controller cycles a drain solenoid on schedule and logs each cycle.
• [Plant dashboard] Pressure curve, leak-rate trend, duty analytics and an event feed (leaks, drains, spikes) on one screen.
• [Calibration procedure] Transducer zero/span check against a reference gauge is part of the buyer's build procedure.

• Working air-line monitor prototype (transducer, solenoid valve, ESP32, reference gauge)
• Complete firmware source code (pressure logging, decay test, duty math, dashboard sync)
• Plant dashboard with pressure curves and leak analytics
• Circuit and wiring documentation
• Transducer calibration procedure (buyer-run zero/span check)
• Project report PDF (compressed-air economics, method, decay-test data from the buyer's run)
• PPT presentation for final review
• Viva Q&A preparation document (pressure transducers, leak estimation, duty cycle, energy cost)

• Leak rate is estimated from pressure decay, not measured by a flow meter — the report states the method and its assumptions honestly.
• The decay test needs a genuine no-demand window; daytime estimates are not attempted.
• The bench rig demonstrates the method on a small receiver; plant-scale piping is out of scope for the prototype.
• Transducer accuracy depends on the buyer's zero/span calibration against the reference gauge.
• Energy-cost figures in the dashboard are computed from duty and nameplate power — indicative, not sub-metered billing data.