IndustrialDesign complete (stages 1–6, rev A), not built, not validated

AirLeak

What your compressed-air leaks cost, measured at the compressor every weekend

Measures how hard your compressors work when the plant is idle and turns it into a weekly dollar figure for leaks, so you know when a leak hunt is worth doing and whether the last one held.

Who buys it: The plant manager or maintenance lead at a small plant with 1–3 screw compressors of any brand; compressed-air service shops resell it.
Why it pays: Example 50 hp plant idling at 40% load: about $9,000/yr of leaks; bringing it to 15% is worth about $5,600/yr (est.).
Target price: $590 kit + $19/site/month; extra compressor CT $79; handheld probe $179 (target)
First-minute wow: A Monday email that says "Idle air last weekend: $175, $9.1k/yr pace, up 12% since your September survey", with the method and its confidence shown.

See the CAD design Concept page

AirLeak concept: the idea and where each part goes — The concept. The CAD design is below, under Printable CAD.

What the research found

And how this design answers it

MEMS mics can't locate leaks in a noisy plant at 80 kHz → no fixed acoustic array; leak quantity is measured at the compressor (current) and header (pressure)
Atlas Copco SMARTLINK is free for Atlas machines → brand-agnostic clamp-on retrofit for any compressor, including old relay-controlled ones
Leak savings were estimates → the weekend figure is the DOE/CAC load-unload measurement (T/(T+t)), run automatically every weekend
Handheld ultrasonic detectors cost $3,495+ → optional $179 40 kHz heterodyne probe for walking a valve bank at 1–3 m
Flow meters ($625+) give cfm, not dollars → works without one; accepts a 4–20 mA meter for VSD compressors
Surveys are one-off → before/after reports prove a repair day paid and alert when leaks creep back

Use case

The weekend leak bill

Plant managerMaintenance techCompressed-air service shop

01Trigger: Saturday to Monday, no production, the compressor keeps loading and unloading
02Detection: the node times every loaded and unloaded interval from the current clamp; the cloud computes 40% idle load ≈ 84 cfm
03Alert: Monday email with $175 this weekend, $9.1k/yr pace and a 12-week trend
04Action: the tech walks the plant with the probe, tags 20 leaks, fixes 15; next weekend's report shows the drop

Outcome: Idle load from 40% to about 15%: about $5,600/yr saved (est.)

How it works

Architecture

01
Sense: 200 A split-core CT per compressor (0.333 V), 0–200 psi header transducer, optional 4–20 mA flow meter
02
Decide (node): ESP32-S3 + ADS131M04 classify each compressor as off, unloaded, loaded or VSD every second
03
Send: 60 s telemetry and state events over MQTT/TLS on Wi-Fi, 7-day flash buffer
04
Decide (cloud): quiet-window detection, leak % by load/unload, drawdown or flow method, kW and $
05
Tell: Monday report, web dashboard, phone app with probe survey and leak list

Hardware

Real parts, buyable today

Bill of materials: about $392 per node kit at qty 1 (transducer $273), about $215 at qty 60 (est.); probe about $30 of parts.

Block	Part	Why this part
MCU + Wi-Fi	ESP32-S3-WROOM-1-N8R8	Wi-Fi, PSRAM for a 7-day buffer, $6.13
ADC	TI ADS131M04 24-bit 4-ch simultaneous	Reads 0.333 V CTs and pressure directly
Current	Magnelab SCT-1250-200 split-core CT	Clamp-on, low-voltage output, up to ~150 hp at 460 V, $44.52
Pressure	Honeywell PX3AN2BS200PSAAX 0–200 psi	Industrial 1/4" NPT, 0.5–4.5 V; drawdown tests
Probe	Murata MA40S4R + NXP SA612A heterodyne + ESP32-C3	40 kHz leak hiss to headphones plus BLE level, for under $40 of parts

Mechanical

Printable CAD

8 parts, generated from code and checked as closed solids. Pick a part to inspect it, or download the STL files to print.

See the CAD parts render

AirLeak printable parts, rendered from the CAD — Render of the printable parts from the actual CAD. Not yet printed or photographed.

Loading the CAD…

Real CAD · drag to rotate · scroll to zoomReal CAD · swipe sideways

Open risks we are working on

Idle demand that isn't leakage (drains, dryer purge, timers) inflates the figure; needs tagging and a zone-off test
VSD compressors: current-to-flow is only ±20% without a flow meter or drawdown test
Pressure transducer cost at qty 1 ($273) squeezes kit margin until volume or a cheaper part is qualified
Plant IT may block Wi-Fi; the LTE-M variant is not designed yet
MA40S4R receiver is not for new designs; the probe needs a second source

Design stage only: nothing on this page is for sale. Specifications and prices are targets.