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No.
7.2.
Procedure for calculating the concentration of the standard gas
The following three elements are required for the calculation.
1.
The temperature of the MB-1 (standard gas box) at the time of gas sampling
2.
The amount of mercury gas sampled by the syringe
3.
The amount of air injected into the Tedlar bag from the PS-4 (or the pump)
[Example of Calculation]
Conditions:
3 mL of mercury gas was sampled from the MB-1, which indicated the
temperature as 25°C.
Gas (air) was injected into the Tedlar bag using the PS-4 (at a flow rate of 1
L/min) for 3 minutes.
→ Because the temperature at the MB-1 is 25°C, the sampled mercury gas concentration is
19.9 ng/mL.
Because 3 mL of gas was sampled, the amount of sampled mercury is 19.9 ng/mL x 3 mL
= 59.7 ng.
Because gas was injected at 1 L/min for 3 minutes, the amount of injected gas is 3 L.
Therefore, the mercury concentration in the Tedlar bag is calculated as follows:
19.9ng/mL x 3mL ÷ 3L ÷ 1000 = 19.9 µg/Nm
* Although you can increase the standard gas concentration by injecting a larger amount
of gas, ensure to limit the amount of mercury gas sampled from the MB-1 each time to
5 mL or less. Otherwise, the mercury chamber inside the MB-1 may not reach the
saturation point, thus leading to a lower mercury concentration in the sampled gas.
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7. Simplified calibration
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