Instruction Manual: EMP-3
NIC-TD-0000067-01
Nippon Instruments Corporation
69
(5)
Inject the mercury gas through the septum within three minutes when the pump is
operating.
(6)
After the pump of the PS-4 stops, close the faucet and remove the Tedlar Bag and septum.
6.5.4.2 CALCULATION PROCEDURE FOR STANDARD GAS CONCENTRATION
The following three factors are necessary for the calculation:
1.
Temperature of the MB-1 (standard gas box) at the time of the gas extraction
2.
Quantity of mercury gas extracted using a syringe
3.
Quantity of air injected from the PS-4 (or pump) to the Tedlar Bag
Example of Calculation
Condition: From the MB-1 with a displayed temperature of 25
C, 3 mL of mercury gas has
been extracted.
Gas (air) has been injected into a Tedlar Bag for three minutes using the PS-4
at a flow rate of 1 L/min.
=> Since the temperature of the MB-1 is 25
C, the concentration of the extracted
mercury gas is 19.9 ng/mL.
Since the extracted volume is 3 mL, the quantity of the extracted mercury is
19.9 ng/mL
3 mL = 59.7 ng.
Since gas has been injected at 1 L/min. for 3 minutes, the quantity of the injected
gas is 3 L.
Therefore, the mercury concentration in the Tedlar Bag is:
19.9 ng/mL
3 mL
3 L/1000 = 0.020 mg/Nm
3
*
Although the standard gas concentration can be heightened by increasing the
quantity of injected gas, make the quantity of mercury gas extracted from the MB-
1 at a time 5 mL or less. Otherwise, the mercury chamber in the MB-1 may not be
saturated and the mercury concentration of extracted gas may become low.
Keep the faucet opened.
