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sensors Issue

Airflow Sensor Failure

Your airflow sensor monitors booth safety. When it fails, you are flying blind. Here is what to do.

Emergency: (877) 489-3727Start Diagnosis

What You're Experiencing

The airflow monitoring sensor (differential pressure sensor, velocity sensor, or airflow transmitter) is not providing accurate readings, has failed...

Visual Signs:

  • Airflow reading stuck at zero or unchanging
  • Reading doesn't match actual airflow conditions
  • Sensor error code on display
  • Manometer disagrees with electronic sensor
  • No alarm when filters are clearly loaded

Sound Signs:

  • No alarm when exhaust fan is off (sensor should alarm)
  • Constant alarming regardless of actual conditions

Safety Risks — Read Before Proceeding

high(NFPA 33 Section 10.3)

Undetected low airflow condition

Action: Use backup monitoring (manometer) until sensor is repaired. Do not paint without airflow verification.

high(OSHA 1910.94)

False sense of security

Action: A sensor reading normal when airflow is actually low puts workers at risk.

Immediate Steps to Take

  1. 1

    Compare electronic sensor reading to manometer (if equipped)

  2. 2

    Verify exhaust fan is running and check if reading changes

  3. 3

    Check sensor tubing for kinks, damage, or disconnection

  4. 4

    Inspect electrical connections to the sensor

  5. 5

    Check for paint overspray on sensor or sensing ports

  6. 6

    Note any error codes displayed

Common Causes

Here are the most likely reasons you're experiencing this problem, ranked by how often we see them.

Sensor Out of Calibration

common

The sensor has drifted from its calibrated settings and is no longer reading accurately. All sensors drift over time.

Plugged Sensing Lines

common

Differential pressure sensors use tubing to sense pressure. These tubes can become clogged with paint overspray or debris.

Electrical Connection Issue

occasional

Wiring connections to the sensor have become loose, corroded, or damaged.

Sensor Element Failure

occasional

The sensing element (pressure diaphragm, hot wire, etc.) has failed due to age, contamination, or damage.

Environmental Damage

occasional

Overspray, solvents, or physical impact has damaged the sensor.

Power Supply Issue

rare

The sensor is not receiving proper power (typically 24VDC or 4-20mA loop powered).

Interactive Diagnostic Tool

Airflow Sensor Failure Diagnostic

Step 1 of 4

Does the manometer show different reading than electronic sensor?

If unsafe at any point: If you cannot verify airflow through any means, do not paint. Solvent vapors can reach explosive concentrations without proper ventilation monitoring.

When to Call WERCS

While some issues can be resolved with basic troubleshooting, these situations require professional service:

  • Sensor readings don't match actual conditions
  • Sensor shows error codes or fault
  • Sensor needs calibration
  • Pressure tubing needs repair or rerouting
  • Sensor replacement is needed
  • You need to upgrade to a more reliable sensor

Priority Service Available

(877) 489-3727

Expert technicians nationwide

Airflow Sensor Failure FAQ

Common questions about this issue

Common types include: differential pressure transmitters (measure pressure drop across filters), velocity sensors (measure air speed directly), and thermal dispersion sensors. Differential pressure sensors are most common because they also indicate filter loading.
Annual calibration is recommended for most airflow sensors. More frequent calibration may be needed in harsh environments or as part of your preventive maintenance program.
Only if you have a backup means of verifying adequate airflow, such as a manometer. NFPA 33 requires monitoring of airflow to ensure safe dilution of flammable vapors. No monitoring = no painting.
Some fluctuation is normal due to variations in airflow. Excessive fluctuation may indicate a loose pressure connection, damaged sensing element, or turbulent air at the sensing point. WERCS can diagnose and correct sensor issues.

Have a question not answered here?

Call us at (877) 489-3727

Related Problems

Airflow AlarmLow AirflowPressure Imbalance

Can't Fix It? We Can.

WERCS expert technicians service paint booths and extraction systems nationwide. 24/7 emergency service available.

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