WPI APOLLO 4000, Instruction Manual

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APOLLO 4000
NITRIC OXIDE DETECTION
WORLD PRECISION INSTRUMENTS C-15
WARNING: Nitric oxide must be handled only in a well-ventilated
area, usually a laboratory fume hood with forced ventilation
. The
U.S. Occupational Safety and Health Administration has set a time-weighted
average maximum NO value as 25 ppm. That is to say that 25 ppm is cited as the
maximum concentration to which workers may be continually exposed. Brief
inhalation of concentrations as low as 200 ppm could produce delayed pulmonary
edema which may be fatal after an asymptomatic period of up to 48 hours after
the initial exposure.
It is therefore critical that the personnel handling
the gas be thoroughly familiar with the Material Safety Data Sheet
(MSDS) and proper handling procedures.
The precautions recommended
by the gas manufacturer must be followed.
Calibration of NO sensor using aqueous
standards prepared with NO Gas
The following method can be used with all NO sensors.
Preparing an NO Standard
This method has the advantage of allowing the user to calibrate NO sensors in the
same environment in which the experimental measurements will be made.
However, it has the disadvantages of added cost, inconvenience, and greater
hazard to the user. All of these factors must be taken into consideration. The setup
for preparing a saturated NO aqueous solution is illustrated in Fig. C5 .
1. Be certain the fume hood is functioning. See Fig. C5 .
2. Make sure that all fittings and connections are secure. The tubing to be used
should not be permeable to NO. We recommend Tygon® tubing if a polymer
tubing is to be used; this is permeable to NO but has the best performance
compared to other polymer tubing of which we are currently aware. Ideally
glass tubing should be used. If Tygon® tubing is used, note that prolonged
exposure to NO affects its properties; therefore it is recommended that the
tubing be inspected frequently and that it be replaced when it appears to be