Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, combustible gas detectors, toxic and harmful gas detectors, and other equipment at various locations. We are licensed to serve nationwide, addressing clients' electrical safety and explosion-proof fire prevention concerns, and contributing to safe production.
Calibration Method
Appearance and structure
Inspect and feel according to requirements of Section 4.1
Logos and Branding
Inspect in accordance with the requirements of Section 4.2.
Power-on Inspection
Inspect visually and by touch, checking the alarm function and alarm action values according to the requirements of 4.3.
Introduce a standard gas substance with a concentration greater than the alarm setting point, causing the instrument to trigger an alarm. Observe whether the instrument's audio-visual alarm is functioning normally and record the instrument's reading when it alarms. Repeat the measurement three times; the arithmetic mean of the three readings is the instrument's alarm action value.

Gas Standard Material
The gas standard substance used should be of the same type as the gas measured by the instrument, such as methane or ethane, or alternative substances like isopropanol can be used. If the instrument does not specify the type of gas being measured, the concentration of the gas at the alarm set point is approximately 60% of the full scale. The uncertainty of the expanded gas standard substance is not more than % (the uncertainty of the gas standard substance is greater than ±1%). The flow indication error of the repetitive dilution device should not be higher than the concentration of the gas standard substance. The concentration unit of the dilution device for the gas standard substance should be converted to match the unit of the tested instrument, and the discrepancy should not exceed 0.%.

What does a calibration report for a flammable gas detector include?
The verification results should be reflected in the verification certificate or report, and the verification proof or report must include the following information.
① Calibration Certificate or Calibration Report
② Laboratory Name and Address;
③ Calibration Location (if not calibrated in the laboratory)
④ Standby Letter of Credit or report (e.g., numbered), with indication of each page and page number.
5. Shipper's name and address
⑥ Describe and clearly identify the target school.
Calibration Date and Receipt Date
⑧ Technical specifications for calibration base, including name and code;
Description of the traceability and validity of the measurement standards used in calibration.
⑩ Description of Calibration Environment
11. Calibration Results and Measurement Uncertainty Statement
12. Signature, title, or equivalent emblem of the issuer of the calibration certificate or report; and issuance date
13. Calibration results are only applicable to the calibration object.
14. No part of the certificate or report may be copied without written consent from the laboratory.
Re-review interval
The recalibration time for instruments is typically 1 year, to be determined by the submitting unit based on actual usage. During the re-certification process, if there are questions about the instrument's test data, or if the main components of the instrument are replaced, or if recalibration is required after repair.

How often should various gas detectors be periodically calibrated and tested?
Instrument recalibration is typically every 1 year, determined by the submitting unit based on actual usage. During the secondary calibration process, if there are any doubts about the instrument's test data, or if the main components of the instrument are replaced, or if recalibration is needed after repairs.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarms, and toxic and harmful gas alarm instruments for regular inspections, metrological measurements, and calibration services. We hold the necessary qualifications to assist clients in solving fire and explosion prevention issues.