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FAQ's
1. How to assemble the Ogawa Passive Sampler? |
CLICK HERE TO VIEW the Assembly Diagram of the Passive Sampler. |
2. What pads are loaded into the Passive Sampler for the collection of each specific gas? |
CLICK HERE TO VIEW the Configuration of the Passive Sampler for various gases. |
3. Can NOx value alone be obtained by just using one NOx pad, if data required by sampling program does not include values for NO or NO2? |
The concentration of NOx cannot be obtained by just using one NOx pad.NOx is a mixture of NO and NO2, so there is no alpha value for NOx.We must use both NO2 and NOx pads for sampling and the two pads are then analyzed separately.The calculation can be done for NO2 and NO separately, and NOx can be calculated by NO2 plus NO.To determine the concentration of NOx, one must use NO2 and NOx pads. |
4. What is the overall measurement procedure? |
5. How to setup the Passive Sampler for outdoor use? |
CLICK HERE TO VIEW the Set Up Diagram for outdoor use of the Passive Sampler. |
CLICK HERE TO VIEW Sample setups for outdoor use of the Passive Sampler. |
6. Does barometric pressure affect collection results? |
As long as the calculations are for units of ppb, the passive sampler measurements are independent of barometric pressure, for any gas. |
7. How to extract the exposed pad for analysis? |
CLICK HERE TO VIEW the Diagram for analyzing the Passive Sampler. |
8. What are the absorption reagents, analytical methods and analytes? |
CLICK HERE TO VIEW the Chart for Reagents, Methods and Analytes. |
9. What is the calculation for concentration in ambient air? |
CLICK HERE TO VIEW the Calculation for concentration in ambient air. |
10. What is the lowest detectable range? |
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NO2 |
24 hr 2.3 ppb |
168 hr 0.32ppb |
NOx |
24 hr 2.3 ppb |
168 hr 0.32 ppb |
SO2 |
24 hr 3.8 ppb |
168 hr 0.54 ppb |
O3 |
24 hr 2.7 ppb |
168 hr 0.39 ppb |
NH3 |
24 hr 2.3 ppb |
168 hr 0.32ppb |
11. What is the upper detectable range? |
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NO2 |
24 hr <25 ppm |
168 hr <3.6 ppm |
NOx |
24 hr <25 ppm |
168 hr <3.6 ppm |
SO2 |
24 hr <25 ppm |
168 hr <3.6 ppm |
O3 |
24 hr <0.8 ppm |
168 hr <0.11 ppm |
NH3 |
24 hr <25 ppm |
168 hr <3.6ppm |
12. What is the normal detectable range? |
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NO2 |
24 hr 0 - 25 ppm |
168 hr 0 - 3.6 ppm |
NOx |
24 hr 0 - 25 ppm |
168 hr 0 - 3.6 ppm |
SO2 |
24 hr 0 - 25 ppm |
168 hr 0 - 3.6 ppm |
O3 |
24 hr 0 - 0.8 ppm |
168 hr 0 - 0.11 ppm |
NH3 |
24 hr 0 - 25 ppm |
168 hr 0 - 3.6 ppm |
Please note that all the above ranges depend on the sensitivity of the analyzing instruments. |
13. What is the recommended sampling height? |
2.5 Meters |
14. What is the response time? (R.T.) |
Response Time = L2/2D = 0.9 (sec.) |
L : Length (cm) D : Diffusion Coefficient (cm2/sec,20 Co) |
15. How to wash the Ogawa Passive Sampler? |
Rinse in Di-ionized water, allow to air dry on clean paper towel. DO NOT USE HEAT |
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