OZONE CALIBRATION TO NIST TRACEABILITY

Calibration Overview

Calibration Date: 08/25/2025

Performed By: Dr. Koz Galatsis, Chief Engineer at Forensics Detectors

Location: Los Angeles, CA – Forensics Detectors Laboratory

Description: OZONE Calibration to NIST Traceable Source

NIST Traceability Chain:

1. A Thermo Electron O3 Primary Standard 49i-PS (Serial Number 072724741), owned by 2B Technologies, referred to as the Transfer Standard. This unit was calibrated to the primary standard by NIST against their Standard Reference Photometer (Serial Number 0) in Gaithersburg, MA on 14/05/2024.
2. A 2B Technologies Model 205 Ozone Monitor was employed as a Working Standard. This unit was calibrated by 2B Technologies to the transfer standard 49i on 31/12/2024.
3. The Forensics Detectors owned 2B Technologies Model 306 Ozone Source (Serial #42) was calibrated to the working standard on 08/06/2025, designated as the Forensics Standard.
4. The Forensics Standard was used to calibrate the "Forensics" standard 49C OZONE Calibrator, Primary Standard, Thermo Environmental Instruments (Serial Number 49CPS-74543-376). This calibration occurred on 08/25/25.

Forensics Detectors OZONE Analyzer: 49C OZONE Calibrator, Primary Standard, Thermo Environmental Instruments, Serial Number 49CPS-74543-376.

Overall Pass / Fail: ✔️

Calibration Conditions: 75F @ 50% RH

Accuracy: Better than 2% of reading from 0-1ppm

Calibrations adjustments to Instrument required?: None. The 49C was in calibration and operating very nicely, stable and accurately per its expected performance & specs. The Cal coefficient factor was left at 1.0000.

2B Technologies Model 306 Ozone Calibration Source™ Calibration Data

Serial Number: 42

Date: 06-Aug-25

Calibration Factors: Z= 2, S= 0.98

Calibration Curve Description: The calibration curve shows a linear relationship with the equation y = 0.9947x + 0.0023 and R² = 1, indicating high correlation.

This unbroken chain of comparisons, based on NIST, ensures that FORENSICS DETECTORS calibrates all its sold ozone meters, detectors, analyzers, and monitors to be NIST traceable. The calibration is performed using either:

• 49C OZONE Calibrator, Primary Standard, Thermo Environmental Instruments, Serial Number 49CPS-74543-376.
• 2B Technologies Model 306 Ozone Source, Serial #42.

Attached Documents:

• Calibration Certificate of 2B Technologies Model 306 (#42)
• Calibration SOP followed: SOP-CAL-002

Signed by: Dr. Koz, Chief Engineer

Date: 08/25/2025

2B Technologies Model 306 Ozone Calibration Source™ Calibration Certificate Details

Calibration Description: NIST Traceable Calibration of Ozone Monitors

Calibration ID Number: 306_042_060825

Location: 2B Tech., 6800 W 117th Ave, Broomfield, CO 80020

Calibration Lab Conditions: 22.9 °C, 29 %RH

Instrument Model: 306

Instrument S/N: 42

Slope: 0.98

Offset, ppbv: 2

Measurement Uncertainty (ppbv): 4.7

2B Spec, Accuracy and Precision: Both: greater of 2 ppbv or 2% of reading

Overall Pass/Fail: ✔️

Working Standard S/N: 773

Transfer Standard Calibration Date: 14-May-24

Working Standard Calibration Date: 31-Dec-24

Date of Calibration: 06-Aug-25

Cal Expiration Date: 05-Aug-26

Calibration Chain: NIST -> Transfer Standard (Thermo Electron 49i-PS) -> Working Standard (2B Tech Model 205) -> Customer's Instrument (2B Tech Model 306).

Cal Performed By: Lizzie Hackler

Calibration Date: 06-Aug-25

2B Technologies Model 306 Ozone Calibration Source™ Calibration Data (Continued)

Serial Number: 42

Date: 06-Aug-25

Calibration Factors: Z= 2, S= 0.98

Calibration Curve with Cal Factors Applied: The calibration curve shows a linear relationship with the equation y = 0.9869x + 2.6195 and R² = 0.9999.

2B Technologies Model 306 Ozone Calibration Source™ Instrument Specifications

Serial Number: 42

Calibration Date: 06-Aug-25

Slope: 0.98

Offset, ppbv: 2

Solenoid Valve: Pneutronics (NPB)

Air Pump: Parker

Ozone Scrubber: Headline

Firmware Version: 5.2B

PCB Version: F

Standard Operating Procedure (SOP-CAL-002): Calibration of Ozone Gas Detectors

1. Purpose and Scope

1.1 Purpose

This Standard Operating Procedure (SOP) describes the method for calibrating ozone (O₃) gas detectors to ensure accurate measurement of ozone concentrations in accordance with ISO/IEC 17025:2017 requirements.

1.2 Scope

This procedure applies to the calibration of ozone detectors and analyzers used for the detection and measurement of ozone gas. The calibration process involves both zero calibration using fresh air or nitrogen, and span calibration using a NIST-traceable calibrated ozone generator and/or ozone analyzer.

2. References

• ISO/IEC 17025:2017 - General requirements for the competence of testing and calibration laboratories
• Manufacturer's operation manual for the specific ozone detector model being calibrated
• Manufacturer's operation manual for the ozone generator and analyzer
• NIST - Certificates of Calibration for ozone generators and analyzers used in calibration

3. Definitions

• Zero Calibration: The process of setting the ozone detector to read zero in an environment free of ozone.
• Span Calibration: The process of calibrating the ozone detector to a known concentration of ozone.
• Ozone Generator: A device that produces controlled concentrations of ozone for calibration purposes.
• Ozone Analyzer: A device that measures ozone concentration, typically using UV absorption principles.
• Transfer Standard: A device that has been calibrated against a NIST-traceable ozone standard.
• LPM: Liters Per Minute, a unit of flow rate.
• ppm: Parts Per Million, a unit of concentration.
• %vol: percentage of volume, a unit of concentration.

4. Responsibilities

4.1 Calibration Technician

• Perform calibrations according to this SOP
• Document all calibration activities
• Verify that all equipment is functioning properly
• Report any anomalies or issues encountered during calibration

4.2 Quality Manager

• Ensure that this SOP is implemented correctly
• Review calibration records
• Approve any deviations from this SOP
• Ensure traceability of reference standards
• Ensure that ozone generators and analyzers maintain their NIST-traceable calibration

5. Equipment and Materials

5.1 Equipment

• Ozone detector/analyzer to be calibrated
• Ozone NIST-traceable standard such as a:
  • NIST-traceable calibrated ozone generator, or
  • NIST-traceable calibrated ozone analyzer
• Calibration cap (as required per ozone detector model)
• Air Flow Meter that reads between 0.5 to 1.5 LPM
• Timer or stopwatch
• Thermometer, humidity meter and barometer for recording environmental conditions

5.2 Materials

• Fresh air, zero air source (ozone scrubber or zero air generator) or nitrogen gas.
• Teflon or other ozone-compatible tubing for connections
• Connecting tubing compatible with the calibration setup

5.3 Verification of Calibration Equipment

• The ozone generator or ozone analyzer must be calibrated against a NIST-traceable standard at least annually
• Maintain calibration certificates for all transfer standards and verification devices
• Perform intermediate checks of ozone generator output using a calibrated ozone analyzer

6. Environmental Conditions

6.1 Required Conditions

• Temperature: 20°C ± 5°C (68°F ± 9°F)
• Relative Humidity: 40% to 60%

6.2 Documentation

Record the environmental conditions at the beginning and end of each calibration procedure. If conditions fall outside the specified ranges, document this as a deviation and assess the impact on calibration results.

7. Calibration Procedure

7.1 Pre-Calibration Checks

1. Verify that the ozone detector is in good working condition with no physical damage.
2. Check battery level to ensure adequate power for calibration.
3. Inspect all calibration equipment, including tubing and all connections.
4. Record the serial numbers of the ozone detector, ozone generator and/or analyzer.
5. Record environmental conditions.
6. Allow all ozone generators and analyzers to warm up for at least 30 minutes.

7.2 Zero Calibration Procedure

1. Power on the ozone detector and allow at least 2 minutes for stabilization in fresh air.
2. If using fresh air for zero calibration: Ensure the calibration area is free from ozone contamination. Allow the detector to stabilize in fresh air for at least 2 minutes.
3. If using zero air for calibration: Connect the zero air source to the ozone detector using the appropriate calibration cap. Set the flow rate between 0.5 to 1.5 LPM. Allow zero air to flow for at least 2 minutes.
4. The ozone detector reading may not read precisely 0 ppm. Depending on the model, it may display 0.0 or 0.00 ppm.
5. Save the zero calibration point to the detector per the ozone detector model instructions.
6. Verify that the real-time display reading shows 0 ppm (or 0.0/0.00 ppm according to the detector's display precision or scale).
7. Record the pre- and post-calibration zero readings.

7.3 Span Calibration Procedure

1. Ensure that zero calibration has been completed successfully before proceeding.
2. Configure the ozone generator to produce the desired calibration concentration. Typical calibration points include ranges from 1 to 20 ppm.
3. Verify the output of the ozone generator using a calibrated ozone analyzer.
4. Connect the ozone generator output to the detector using an appropriate calibration cap or equivalent.
5. Using the air flow meter confirm ozone gas is being delivered between 0.5 to 1.5 LPM.
6. Expose the ozone detector to the generated ozone for 2 minutes or until the reading has stabilized. Document any deviation from the standard exposure time.
7. Verify that the displayed ozone value has stabilized.
8. Save this span calibration point to the ozone detector per instructions of the ozone detector model.
9. Record the following:
   • Pre-calibration reading (before adjusting)
   • Span Gas Ozone Concentration (obtained from the Ozone Analyzer)
   • Post-calibration reading
10. Allow the detector to return to fresh air or zero air and verify that the reading returns to zero.

7.4 Calibration Verification

1. After completing all calibration steps, verify the calibration by exposing the detector to the reference gas again.
2. Record the verification reading.
3. The reading should be within ±5% of the reference ozone gas concentration.
4. If verification fails, repeat the calibration procedure.

8. Documentation and Records

8.1 Required Documentation

For each calibration performed, record the following information:

1. Date and time of calibration
2. Calibration technician name
3. Ozone detector information:
   • Manufacturer and model
   • Serial number
4. Ozone generator/analyzer information:
   • Manufacturer and model
   • Serial number
   • Calibration certificate number
   • Calibration due date
5. Environmental conditions:
   • Temperature
   • Relative humidity
6. Calibration results:
   • Pre-calibration zero reading
   • Post-calibration zero reading
   • Generated ozone concentration as verified from ozone analyzer
   • Pre-calibration span reading
   • Post-calibration span reading
7. Any deviations from this SOP
8. Any observations or comments

8.2 Calibration Certificate

Upon successful completion of calibration, issue a calibration certificate that includes:

1. Title: "Certificate of Calibration"
2. Laboratory name and address
3. Unique identification of the certificate
4. Customer name and address
5. Identification of the calibration method used
6. Description and identification of the ozone detector
7. Date of calibration
8. Calibration results
9. Environmental conditions
10. Signature of the person authorizing the certificate
11. Statement that results relate only to the items calibrated
12. Statement on measurement uncertainty
13. Reference to the traceability of measurements to NIST standards

9. Uncertainty Analysis

Calculate and report the measurement uncertainty for each calibration according to the laboratory's uncertainty estimation procedure. The uncertainty is calculated as 95% confidence of the final calibration reading with a K factor equaling to 2. Items considered includes:

• Ozone gas uncertainty (from Certificate of Calibration)
• Environmental conditions
• Equipment resolution
• Repeatability
• Detector Drift during Calibration
• Effect of gas flow rate

10. Quality Control

10.1 Regular Checks

• Perform regular checks of ozone generator output using a calibrated ozone analyzer.
• Perform annual verification of transfer standards against a higher-level standard.
• Perform regular quality control checks on calibration equipment (as required).

10.2 Non-conforming Work

If any part of the calibration process does not conform to this SOP:

1. Document the non-conformance.
2. Evaluate the impact on calibration results.
3. Take corrective action as necessary.
4. Notify the customer if results are affected.

11. Revision History

12. Approvals

Appendix 1: Example Certificate of Calibration

Example Certificate of Calibration - for a Single Ozone Gas Detector / Analyzer.

Specific Certificate of Calibration

Customer Name: Robert Olsen

Customer Address: Incline, NV, 89451

Calibration Location: 777 Silver Spur Road, Suite #130, Rolling Hills Estates, CA, 90274, USA

Test Conditions: Temperature: 73F ±1%, Humidity: 59% RH ±1%

Calibration Method ID: SOP-CAL-002

Certificate Number: 33175-23060303

Manufacturer: Forensics Detectors

Model Number: FD-90A-O3-LOW

Reference Gas(s): OZONE (O3)

Serial Number: 23060303

Reference Ozone: #042

Last Calibrated: 05/30/2025

Analyzer Serial: (Not specified for this certificate)

Inspection Results

• Visual Inspection?: Normal, no anomalies ✔️
• Detector Functionality?: Normal, no anomalies ✔️
• Alarm Functionality?: Normal, no anomalies ✔️

Calibration Test Results

Other Comments: N/A

Calibration Technician Name and Signature: Mr. Austin Jun

Date of Calibration: 05/30/2025

Certificate Issue Date: 05/30/2025

Next Cal Due Date: 05/30/2026

The calibration results reported in this certificate relate only to the specific instrument / reference gas identified herein and are valid only for the conditions under which the calibration was performed. The reported expanded uncertainty of measurement is stated as the standard uncertainty of measurement multiplied by the coverage factor k=2, which for a normal distribution corresponds to a coverage probability of approximately 95%. All measurements performed during this calibration are traceable to the International System of Units (SI) through the National Institute of Standards and Technology (NIST). This certificate shall not be reproduced except in full, without written approval from Forensics Detectors.