RÉTTARFRÆÐINGARGREINDIR FD-91 gasskynjarar

Tilgangur og umfang

Tilgangur
Þessi staðlaða verklagsregla (SOP) lýsir aðferðinni til að kvarða gasskynjara til að tryggja nákvæma mælingu á tilteknum gasstyrk í samræmi við kröfur ISO/IEC 17025:2017.

Gildissvið
Þessi aðferð á við um kvörðun færanlegra gasskynjara sem notaðir eru til að greina og mæla lofttegundir í töflunni hér að neðan. Kvörðunarferlið felur í sér bæði núllkvörðun með fersku lofti eða köfnunarefni og mælikvarðakvörðun með NIST-rekjanlegum viðmiðunarlofttegundum eins og fram kemur í töflunni hér að neðan.

Markmið Gasheiti	Efnatákn	Gassvið
Asetýlen	C2H2	0-50 ppm
Súrefni	O2	0% – 21%
Etýlen	C2H4	0-80 ppm
Klór	Cl2	0-10 ppm
Kolmónoxíð	CO2	0-5000 ppm
Koltvíoxíð	CO2	0 – 100 %vol
Etýlenoxíð	ETO	0-10 ppm
Metan	CH4	0 – 50 %LEL
Vetni	H2	0-5,000 ppm
Brennisteinsvetni	H2S	0-100 ppm
Formaldehýð	CH2O	0-10 ppm
Klórvetni	HCl	0-10 ppm
Vetnisýaníð	HCN	0-20 ppm
Nitur	N2	0 – 100 %vol
Ammoníak	NH3	0-50 ppm
Nituroxíð	N2O	0-200 ppm
Köfnunarefnisdíoxíð	NO2	0-200 ppm
Fosfín	PH3	0-10 ppm
Brennisteinsdíoxíð	SO2	0-10 ppm
Ísóbútýlen	C4H8	0-50 ppm
Argon	Ar	0-100 %rúmmál
Helíum	He	0-100 %rúmmál
Nituroxíð	NEI	0-1000 ppm
Etanól	C2H6O	0-500 ppm

Heimildir

• ISO/IEC 17025:2017 – General requirements for the competence of testing and calibration laboratories
• Manufacturer’s operation manual for the specific gas detector model being calibrated
• NIST – Certificates of Analysis for reference gases used in calibration

Skilgreiningar

• Zero Calibration: The process of setting the gas detector to read zero in an environment free of the target gas.
• Span Calibration: The process of calibrating the gas detector to a known concentration of the target gas.
• Reference Gas: A gas with a known concentration that is NIST-traceable and used as a standard for calibration.
• LPM: Liters Per Minute, a unit of flow rate.
• ppm: Parts Per Million, a unit of concentration.
• %vol: percentage af rúmmáli, eining fyrir styrk.

Ábyrgð

Calibration Technician

• Pefform calibrations according to this SOP
• Document all calibration activities
• Verity that all equipment is finctioning prorrly
• Report any anomalies or issues encountered during calibration

Gæðastjóri

• Ensure that this SOP is implemented correctly
• Review calibration records
• Approve any deviatioms from this SOP
• Ensure traceability of reference standards

Búnaður og efni

Búnaður

• Gas detector to calibrated
• Calibration cap (as required per gas detector model)
• Flow regulator capable of delivering 0.5 LPM
• Tímamælir eða skeiðklukka
• Thermometer and humidity for recording environmental conditions

Efni
NST-traceab1e reference gas cylinders with appropriate concentrations for the target gas
Zero air or nitrogen cylinder (if fresh air is not suitable for zero calibration)
Connecting tubing compatible with the calibration gas

Umhverfisskilyrði

Nauðsynleg skilyrði
Temperature: 2crc SOC (68T 90F)
Relative Humidiry: 40% to 60%

Skjöl
Skráið umhverfisaðstæður í upphafi og lok hverrar kvörðunarferlis. Ef aðstæður falla utan tilgreindra marka skal skrá það sem frávik og meta áhrif þess á kvörðunarniðurstöður.

Kvörðunaraðferð

Pre-Calibration Checks

1. Verify that the gas 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. Verify that reference gas cylinders are within their validity period.
5. Record the serial number of the gas detector and the certificate numbers of reference gases.
6. Skráið umhverfisaðstæður.

Núllkvörðunaraðferð

1. Power on the gas detector and allow 2 minutes for stabilization in fresh air.
2. If using fresh air for zero calibration: a. Ensure the calibration area is free from target gas contamination. b. Allow the detector to stabilize in fresh air for at least 2 minutes.
3. If using nitrogen for zero calibration: a. Connect the nitrogen cylinder to the gas detector using the appropriate calibration cap. b. Set the flow rate to 0.5 LPM. c. Allow nitrogen to flow for at least 2 minutes.
4. The gas detector reading may not read precisely 0 ppm. Depending on the model, it may display 0.0 or 0.00 ppm. Depending on the scale it may also read in %vol.
5. Save the zero calibration point to the detector per the gas 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 %vol).
7. Record the pre- and post-calibration zero readings.

Spannkvörðunaraðferð

1. Ensure that zero calibration has been completed successfully before proceeding.
2. Connect the reference gas cylinder to the gas detector using a calibration cap or equivalent.
3. Set the flow rate to 0.5 LPM.
4. Expose the gas analyzer to the reference gas for 1 minute or until the reading has stabilized. Document any deviation from the standard exposure time.
5. Verify that the displayed gas value has stabilized.
6. Save this span calibration point to the gas detector per instructions of the gas detector model.
7. Skráðu eftirfarandi:
   Pre-calibration reading (before adjusting)
   Span gas concentration from the Certificate of Analysis Post-calibration reading
8. Allow the detector to return to fresh air and verify that the reading returns to zero.

Multi-Sensor Gas Calibration
Fyrir gasskynjara með fleiri en einum gasskynjara sem þarfnast kvörðunar fyrir fleiri en eitt markgas:

1. Repeat the zero and span calibration procedure (Section 7.2 and 7.3) for each target gas.
2.  A mixed reference gas can be used to expose a multi-sensor gas detector. Undertake zero and span calibration simultaneously for each gas sensor within the multi-gas detector.
3. If a mixed reference gas is not available, treat each gas sensor separately and following Section 7.2 and 7.3.
4. Document the calibration results for each sensor separately (but on the same gas detector calibration certificate).

Staðfesting kvörðunar

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 ±4% of the reference gas concentration.
4. If verification fails, repeat the calibration procedure.

Skjöl og skrár

Nauðsynleg skjöl
Fyrir hverja kvörðun sem framkvæmd er skal skrá eftirfarandi upplýsingar:

1. Dagsetning og tími kvörðunar
2. Calibration technician name
3. Gas detector information:
   • Framleiðandi og módel
   • Raðnúmer
4. Reference gas information:
   • Gas type and concentration
   • Strokkanúmer
   • Skírteinisnúmer
   • Gildistími
5. Umhverfisskilyrði:
   • Hitastig
   • Hlutfallslegur raki
6. Niðurstöður kvörðunar:
   • Pre-calibration zero reading
   • Post-calibration zero reading
   • Pre-calibration span reading
   • Reference gas concentration used
   • Post-calibration span reading
7. Any deviations from this SOP
8.  Any observations or comments

Kvörðunarvottorð
Þegar kvörðun er lokið með góðum árangri skal gefa út kvörðunarvottorð sem inniheldur:

1. Title: “Certificate of Calibration”
2. Laboratory name and address
3. Unique identification of the certificate
4. Identification of the calibration method used
5. Description and identification of the gas detector
6. Dagsetning kvörðunar
7. Niðurstöður kvörðunar
8. Umhverfisaðstæður
9. Signature of the person authorizing the certificate
10. Statement that results relate only to the items calibrated
11. Statement on measurement uncertainty
12. Reference to the traceability of measurements to NIST standards

Uncertainty Analysis

Reiknið út og greinið frá mælióvissu fyrir hverja kvörðun samkvæmt óvissumatunaraðferð rannsóknarstofunnar. Óvissan er reiknuð sem 95% öryggi loka kvörðunarmælingarinnar með K-stuðli sem jafngildir 2. Meðal atriða sem skoðuð eru:

1. Reference gas uncertainty (from Certificate of Analysis)
2. Umhverfisaðstæður
3. Equipment resolution
4. Endurtekningarhæfni
5. Detector Drift during Calibration
6. Effect of gas flow rate

Gæðaeftirlit

Regluleg eftirlit

1. Paform regular checks of reference gases using secondary standards-
2. Perform regular quality control checks on calibration equipment (as required)-

Non-conforming Work 

Ef einhver hluti kvörðunarferlisins er ekki í samræmi við þessa staðlaða verklagsreglu:

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.

Endurskoðunarsaga

Endurskoðun	Dagsetning	Lýsing á breytingum	Samþykkt af
1.0	16. maí 2025	Upphafleg útgáfa	Gæðastjóri

Samþykki

Hlutverk	Nafn	Undirskrift	Dagsetning
Höfundur	Dr. Koz Galatsis	Dr. Koz Galatsis	08/25/2025
Tæknileg viðrviewer	Dr. Koz Galatsis	Dr. Koz Galatsis	08/25/2025
Gæðastjóri	Dr. Koz Galatsis	Dr. Koz Galatsis	08/25/2025

VIÐAUKI 1
ExampKvörðunarvottorð – fyrir stakan gasskynjara.

Vottorð um kvörðun USA NIST Traceability Calibration
				Kvörðunarstaðsetning: 777 Silver Spur Road, Suite #130 Rolling Hills Estates, CA, 90274, Bandaríkjunum
Prófunarskilyrði:	Hitastig: 70°C ±1%, Rakastig: 52% RH ±1%
Calibration Method ID:	SOP-CAL-001			Vottunarnúmer:			4567
Framleiðandi:	Réttarmeinafræðingar			Gerðarnúmer skynjara:			FD-90A-CO
Reference Gas(s):	CO			Raðnúmer skynjara:			245686867
Cylinder Lot Number:	304-403306989-1			Gildistími viðmiðunargass:			04/05/2029
NIÐURSTÖÐUR SKOÐUNAR
Visual Inspection?		Normal, no anomalies						PASS
Detector Functionality?		Normal, no anomalies						PASS
Virkni viðvörunar?		Normal, no anomalies						PASS
NIÐURSTÖÐUR KVÖRÐUNARPRÓFA
Gasheiti		CO
Reference Gas Concentration		200 ppm
Útvíkkuð óvissa 5% (k=2, 95% öryggisstig)		±10 ppm
Pre Zero Calibration (As Found)		0 ppm
Post Zero Calibration (As Left)		0 ppm						PASS
Pre Span Calibration (As Found)		189 ppm
Post Span Calibration (As Left)		200 ppm						PASS
Aðrar athugasemdir: N/A
Nafn og undirskrift kvörðunartæknimanns: Austin Jun					Date of Calibration: 05/23/2025 Certificate Issue Date: 05/23/2025 Next Cal Due Date: 05/23/2026
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.

VIÐAUKI 2
ExampKvörðunarvottorð – fyrir fjölgasskynjara með 4 gasskynjurum.

Vottorð um kvörðun USA NIST Traceability Calibration
				Kvörðunarstaðsetning: Forensics Detectors, 777 Silver Spur Road, Suite #130 Rolling Hills Estates, CA, 90274, Bandaríkjunum
Prófunarskilyrði:	Hitastig: 70°C ±1%, Rakastig: 52% RH ±1%
Calibration Method ID:	SOP-CAL-001			Vottunarnúmer:			4567
Framleiðandi:	Réttarmeinafræðingar			Gerðarnúmer:			FD-4S
Reference Gas(s):	O2, CO, H2S, CH4			Raðnúmer:			245686867
Cylinder Lot Number:	304-403306989-1			Gildistími viðmiðunargass:			04/05/2029
NIÐURSTÖÐUR SKOÐUNAR
Visual Inspection?		Normal, no anomalies						PASS
Detector Functionality?		Normal, no anomalies						PASS
Virkni viðvörunar?		Normal, no anomalies						PASS
NIÐURSTÖÐUR KVÖRÐUNARPRÓFA
Gasheiti		CH4	O2		CO	H2S
Reference Gas Concentration		50% LEL	20.9% bindi		200 ppm	25 ppm
Útvíkkuð óvissa 5% (k=2, 95% öryggisstig)		±3 %LEL	±1%vol		±10 ppm	±1 ppm
Pre Zero Calibration (As Found)		0% LEL	0.0%		0 ppm	0 ppm
Post Zero Calibration (As Left)		0% LEL	0.0%		0 ppm	0 ppm		PASS
Pre Span Calibration (As Found)		40% LEL	20.9%		200 ppm	25 ppm
Post Span Calibration (As Left)		50% LEL	20.9%		200 ppm	25 ppm		PASS
Aðrar athugasemdir: N/A
Nafn og undirskrift kvörðunartæknimanns: Herra Austin Jun Austin Jun					Date of Calibration: 05/23/2025 Certificate Issue Date: 05/23/2025 Next Cal Due Date: 05/23/2026
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.

Skjöl / auðlindir

RÉTTARFRÆÐINGARGREINDIR FD-91 gasskynjarar [pdfNotendahandbók FD-91 gasskynjarar, FD-91, gasskynjarar, skynjarar

Heimildir

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