Gastec Instructions for No. 92L Acetaldehyde Detector Tube
FOR SAFE OPERATION
Carefully read this manual and the instruction manual of your Gastec Gas Sampling Pump.
WARNING
- Use only Gastec detector tubes in a Gastec pump.
- Do not interchange or use non-Gastec parts or components in Gastec's detector tube and pump system.
- Using non-Gastec parts or components in Gastec's detector tube and pump system or using a non-Gastec detector tube with a Gastec pump or using a Gastec detector tube with a non-Gastec pump may damage your detector tube and pump system, or may cause serious injuries, or death to the end-user. It will also void all warranties, and guarantees regarding performance and data accuracy.
CAUTION
If you do not observe the following precautions, you may suffer injuries or damage the product.
- When breaking the tube ends, keep away from eyes.
- Do not touch the broken glass tubes, broken pieces and reagent with bare hand(s).
- The sampling time represents the time necessary to draw the air sample through the tube. The tube must be positioned in the desired sampling area for the entire sampling time or until the flow finish indicator indicates the end of the sampling.
NOTES
For maintaining performance and reliability of the test results, observe the following.
- Use Gastec Gas Sampling Pump together with Gastec Detector Tubes only for the purposes specified in the instruction manual of the detector tube.
- Use this tube within the temperature range of 5 - 40 °C (41 - 104 °F). If this tube were used below 5 °C (41 °F), the demarcation of the tube would be generated as a faint discolouration.
- Use this tube within the relative humidity range of 20 - 90%.
- This tube may be interfered with by the coexisting gases. Please refer to the table "INTERFERENCES" below.
- The shelf life and storage condition of the tube are marked on the label of the tube box.
APPLICATION OF THE TUBE
Use this tube for detecting acetaldehyde in the air or in industrial areas and for determining the environmental atmospheric condition.
SPECIFICATION
(Because of Gastec's commitment to continued improvement, specifications are subject to change without notice.)
The detector tube is a glass tube with a scale marked from 1 to 20 ppm, featuring specific calibration points at 1, 2, 4, 6, 8, 10, 12, 14, and 20. The left end of the tube contains a yellow detecting layer. A 'G' symbol and '92L' are printed on the tube. The measurement is indicated by the color change at the interface between the stained reagent (turning reddish brown) and the unstained reagent.
| Measuring Range | 1 - 20 ppm |
| Number of Pump Strokes | 1 |
| Stroke Correction Factor | 1 |
| Sampling Time | 2 minutes per pump stroke |
| Detecting Limit | 0.2 ppm (n = 1) |
| Colour Change | Yellow ➔ Reddish brown |
| Reaction Principle | 3CH₃CHO + (NH₂OH)₃H₃PO₄ → H₃PO₄ H₃PO₄ + Base → Phosphate |
| Coefficient of Variation | 10% (for 1 to 6 ppm), 5 % (for 6 to 20 ppm) |
| Shelf Life | Please refer to the validity date printed on the tube box. |
| Storage Condition | Store the tubes at 10°C (50°F) or below in a refrigerator. |
CORRECTION FOR TEMPERATURE, HUMIDITY AND PRESSURE
Temperature
Correct for temperature with the table below.
| Temperature °C (°F) | 5(41) | 10(50) | 15(59) | 20(68) | 25(77) | 30(86) | 35(95) | 40(104) |
|---|---|---|---|---|---|---|---|---|
| Correction Factor | 1.05 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 0.95 |
Humidity
No correction is required between 20 - 90% R.H.
Pressure
To correct for pressure, use the formula below:
Tube Reading* (ppm) × [1013 (hPa) / Atmospheric Pressure (hPa)]
* This value is after other correction(s), if any, are applied.
MEASUREMENT PROCEDURE
- For checking the leakage of the pump, insert a freshly sealed detector tube into the pump. Follow the instructions provided with the pump operation manual.
- Break the tips off the fresh detector tube with the tube tip breaker in the pump.
- Insert the tube into the pump inlet with the arrow [➡️] on the tube pointing toward the pump.
- Make certain the pump handle is all the way in. Align the guide marks on the pump body with the guide marks on the handle.
- Pull the handle all the way out until it locks at one pump stroke (100 mL). Wait two minutes and confirm the completion of the sampling.
- Read the concentration level at the interface where the stained reagent meets the unstained reagent.
- If temperature correction is necessary, obtain the true concentration by using the temperature correction factor.
- If pressure correction is necessary, use the pressure correction formula.
INTERFERENCES
| Substance | Concentration | Interference | Changes colour by itself to |
|---|---|---|---|
| Ketones | + | Reddish brown | |
| Aldehydes | + | Reddish brown | |
| Acid Gases | + | Reddish brown | |
| Ammonia | ≤30 ppm | No | No discolouration |
| Acetic Acid | ≥2 times | + | Reddish brown |
This table of interference gases primarily expresses the interference of each coexisting gas in the concentration range, that is equivalent to the gas concentration. Therefore, the test result may show positive results due to other substances not listed in the table. If more information is needed, please contact us or our distributors in your territory.
DANGEROUS AND HAZARDOUS PROPERTIES
Threshold Limit Value-Ceiling by ACGIH (2021): 25 ppm
INSTRUCTIONS ON DISPOSAL
The reagent of the tube does not use toxic substances. When disposing the tube regardless of whether it has been used or not, follow the rules and regulations of your local government.
WARRANTY
If you have any questions regarding gas detection and the quality of the tubes, please feel free to contact your Gastec representatives.
Manufacturer: Gastec Corporation
8-8-6 Fukayanaka, Ayase-City, Kanagawa 252-1195, Japan
https://www.gastec.co.jp/
Telephone +81-467-79-3910 Facsimile +81-467-79-3979
IM0092LE5 Printed in Japan 22C1D
