False Alarm Risk Calculator

Enter Project Details

Use realistic values from site logs, surveys, and maintenance plans.

Alarm system type *

Baseline nuisance tendency differs across system categories.

Work environment *

Exposure increases with dust, weather, and activity.

Detector sensitivity (1–5) *

Higher sensitivity can raise nuisance triggers in dusty zones.

Device age (years)

Older devices may drift and need replacement planning.

Past false alarms (per month)

Use average from the last 3–6 months if available.

Dust level (0–5)

0=clean, 5=heavy cutting/grinding or demolition dust.

Relative humidity (%)

Extreme swings from ~45% can increase false activations.

Vibration / impact level (0–5)

Consider compactors, hammer drills, and heavy plant movement.

Electrical noise level (0–5)

Generators, welders, and long runs can add interference.

Maintenance interval (days) *

Intervals above ~30 days usually increase nuisance risk.

Commissioning quality (1–5) *

5=excellent zone tuning; 1=unverified or rushed setup.

Operator training level (1–5) *

Higher training reduces accidental activations and bypass errors.

Redundancy configuration

Redundancy can reduce nuisance activations.

Verification control

Verification reduces false dispatch and downtime.

Reset Exports appear after a successful calculation.

Example Data

Sample scenarios to show typical inputs and outputs.

Scenario	Environment	Sensitivity	Dust	Maintenance (days)	False alarms/month	Typical risk level
Fit-out, controlled site	Indoor (clean finish work)	2	1	30	0.5	Low–Moderate
Active build, mixed trades	Indoor (active build/fit-out)	3	3	45	1.5	Moderate
Demolition, heavy dust	Demolition / heavy dust	4	5	60	4.0	High–Critical

Your actual score depends on all factors and risk reducers.

Formula Used

A weighted risk model with a probability mapping.

Each factor is converted to a 0–100 component risk, then combined:

Weighted score

Score = Σ( weightᵢ × componentRiskᵢ ) + redundancyAdjust + verificationAdjust

The 30‑day probability is estimated using a logistic curve:

P(30d) = 1 / ( 1 + e^{−(Score−50)/10} )

This is a practical planning estimate, not a warranty or code compliance result.

How to Use This Calculator

A quick workflow for construction teams and supervisors.

Collect recent alarm logs and count false alarms per month.
Walk the site and rate dust, vibration, and electrical noise.
Enter the maintenance interval and commissioning quality rating.
Set detector sensitivity to match the current site conditions.
Choose redundancy and verification controls, if installed.
Click Calculate Risk to view results above the form.
Export CSV or PDF for meetings, audits, and corrective actions.

Good practice

Re-run the calculator after major site changes, weather shifts, or detector relocation.

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