Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the certification, calibration, and metrological services for gas detectors, flammable gas detectors, and toxic gas detection instruments for various locations. We provide qualifications and services nationwide, addressing all kinds of electrical safety and explosion-proof fire prevention issues for our clients, and contributing to safe production.
Gas Standard Material
We use gas standard substances with the same type as the gas measured by the instrument, such as methane or gas standards that can be ethyl alcohol, etc. If the instrument does not specify the type of gas being measured, the concentration of the gas with a 60% setting point for the gas alarm is approximately the full scale. The uncertainty of the expanded gas standard substance is not significant (%). The flow indication error of the repeatability dilution device for gas standard substances with a concentration greater than 1% should not be higher. The concentration unit of the dilution device for gas standard substances should be converted to match the measuring unit of the inspected instrument. The conversion should not exceed 0.%.

Appearance and structure
Instruments should not have any surface damage that affects their normal operation. The surface of newly manufactured instruments should be smooth and even, with a uniform paint and coating, free from peeling or rusting.
The instrument's connections are reliable, and all dials or buttons should operate and control normally.
Branding and Logos
Instrument name, model, manufacturer's name, manufacturing date, serial number, explosion-proof markings and numbers, as well as the manufacturing measurement instrument license mark and number for domestic instruments should be clear.

What information is included in the calibration report for a combustible gas detector?
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 Certificate or report (e.g., numbered), indicating page number and total pages for each;
Please provide the name and address of the shipping entity.
⑥ Describe and clearly identify the school's target audience.
Date of calibration and receipt;
⑧ Technical specifications for calibration base, including name and code;
Description of the traceability and validity of the measurement standards used for calibration.
⑩ Description of Calibration Environment
11. Calibration Results and Measurement Uncertainty Statement
12. Signature, title or equivalent mark, and issuance date of the certifier or issuer of the calibration certificate or report.
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.
Reproofreading interval
The recalibration period for instruments is typically one year, which is 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, as well as after repairs, recalibration is required.

What factors can influence the calibration cycle of flammable gas detectors?
Manufacturer Requirements: Different manufacturers may have varying inspection cycle requirements for flammable gas detectors. Therefore, when purchasing equipment, carefully review the product manual to understand the specific requirements of the manufacturer.
Equipment Operating Environment: The operating environment of the alarm directly affects its inspection cycle. If the equipment is frequently exposed to high concentrations of harmful gases, high or low humidity, or high or low temperatures, its inspection cycle may be shortened accordingly.
‌Equipment Maintenance Status: The condition of equipment maintenance is also a significant factor affecting the inspection cycle. If the equipment frequently encounters issues such as battery depletion and sensor aging, the inspection cycle will accordingly be shortened.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party service provider specializing in electrical safety, electrical explosion-proofing, gas alarm systems, and toxic/hazardous gas alarm instruments, offering regular calibration, metrological testing, and certification services. We are qualified to address fire and explosion prevention issues for our clients.