Skip to content
IEMI Labs
All product designs
SensingDesign complete (stages 1–6, pilot rev A), not built, not validated

WetCheck

An alarm when a stone saw runs without water, plus a shop dust trend

When a stone saw, grinder or polisher draws current but its water isn't flowing, a beacon and buzzer go off at that station within 2 seconds, and every tool-on minute is logged as wet or dry so the shop has evidence that it cuts wet. Early warning and evidence only: never a silica level or exposure figure.

Who buys it
Owner of a countertop or stone fabrication shop with 1–5 cutting stations, sold through workers' comp carriers, slab distributors and industrial hygienists.
Why it pays
Fewer ruined diamond blades and polishing pads from dry running, and monthly records without paperwork. Expected silicosis liability avoided is about $9k/yr per shop on research assumptions (est.), mostly carried by insurers.
Target price
$299 per station + $10/month; 3-station kit with one dust monitor $799 + $25/month (target)
First-minute wow
Switch on a polisher with the valve closed and the beacon turns yellow in 2 seconds; open the valve and it goes back to green, with the event already in the log.
See the CAD designConcept page
WetCheck 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

  • Camera plume AI is costly and doesn't answer the real question → dropped; tool current plus water flow answer "is it cutting dry?" for about $30 in sensors
  • Optical PM can't measure silica → shop-level SPS30 raises only a relative "dust event" against its own 7-day baseline; no µg/m³ is ever shown
  • Mains wiring in a wet shop → nothing printed carries mains; corded tools go through a UL-listed Shelly plug, hard-wired saws get a listed RIBXGTA current switch fitted by an electrician
  • Slurry, spray and hosing down → IP65-by-design housings with silicone-cord gaskets, glands on the bottom face and a stand-off wall bracket
  • Flow sensors clog on slurry → sensor on the clean supply hose behind a Y-strainer; a fouled rotor gives a false alarm, not a missed one
  • Logs of dry cuts could be used against the owner → owner owns the data and approves every insurer report; each event shows the corrective action

Use case

Hose kinked mid-cut

Shop ownerSaw operatorWetCheck station and beaconWetCheck cloud

  1. 01Trigger: at 10:42 a slab cart kinks the bridge saw's supply hose while the operator is cutting quartz
  2. 02Detection: the current switch shows the spindle on while flow drops from 6.2 to 0.3 L/min, below this station's 2.0 L/min threshold
  3. 03Alert: yellow beacon and chirp at 2 s, red and continuous buzzer at 5 s, and a WhatsApp/SMS to the owner in Spanish and English
  4. 04Action: the operator mutes the buzzer, stops the saw and frees the hose; the app asks the owner for the cause

Outcome: Dry cutting lasted 41 seconds instead of until the next inspection, and the cause is on record for the monthly report

How it works

Architecture

  1. 01

    Sense: tool current from a Shelly plug or RIBXGTA current switch; water flow from a Hall or turbine flow sensor; shop dust from an SPS30 with an SHT40 mist flag

  2. 02

    Decide: station firmware raises WARN at 2 s and DRY at 5 s of tool-on without flow; logs every tool-on minute as wet or dry

  3. 03

    Send: ESP32-S3 over Wi-Fi, MQTT over TLS to the cloud rules engine

  4. 04

    Tell: tower beacon and buzzer at the station, WhatsApp/SMS to the owner, a Spanish/English app, and an owner-approved monthly evidence report

Hardware

Real parts, buyable today

Bill of materials: about $150 per station and about $93–95 per dust node at qty 1 (est.).

BlockPartWhy this part
MCUAdafruit ESP32-S3 Feather on a carrier PCBWi-Fi, pulse counting for flow, secure boot; solder-free prototype
Tool on (corded)Shelly Plug US Gen4 (UL listed, 15 A)A listed product carries the mains; we only read its current
Tool on (hard-wired)Functional Devices RIBXGTA split-core current switchDry Class-2 output, installed by an electrician
Water flowYF-S201 Hall sensor (Gems FT-110 turbine option; low-flow sensor for handhelds)Only flowing-or-not against a threshold is needed
BeaconAdafruit #2993 R/Y/G tower light + buzzer, 12 VVisible from the saw; colours need no language
Dust monitorSensirion SPS30 + SHT40Relative dust trend; mist flag avoids false dust events

Mechanical

Printable CAD

10 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
WetCheck 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

  • Implied-safety and product liability cannot be designed away; insurance and a lawyer review are needed before the first field unit
  • The Shelly plug's 15 A rating is marginal for a 15 A saw at full load, and whether its listing covers shop use is unconfirmed
  • SPS30 fouling rate in shop dust is unknown (kill criterion: fouls in under 2 weeks)
  • If bridge saws already have water interlocks, the market narrows to handheld tools
  • IP65 is a design target only, checked with a bench jet test, not certified
  • Small market (about $6M SAM est.); owners may still read the dust trend as an exposure figure

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