YOKOGAWA EXAxt ZR22G, User Manual, Page: 44 / 211

<2. Specifications>
2-25
IM 11M12A01-02E 16th Edition : Mar. 19, 2020-00
< Pressure setting for the ejector assembly for high temperature use >
Pressure supply for the ejector assembly should be set so that the suction flow of the sample gas
becomes approximately 5 l/min.
To set this, proceed as follows:
(1) In Graph 4, draw a horizontal line from the 5 l/min point. on the vertical axis (Suction flow:
Qg) toward the gas pressure line to be used, to find the point of intersection.
Draw a line vertically down from the point of intersection to the axis to find the drive
pressure, P (at the ejector entrance).
(2) In Graph 1, determine Po (pressure setting) from L (the distance between the ejector and
the pressure gauge).
(3) Open the needle valve to supply air for the ejector to the pressure gauge until it indicates the
pressure setting, Po.
NOTE
Qg (the suction flow) may require change according to the conditions of use. Refer to Section
3.2.1 and Section 4.1.4 for details.
Graph explanation
(1) Graph 1 is to compensate for pressure loss in piping between the ejector and the pressure
gauge, and find Po (pressure setting).
(2) Graph 2 shows correlation between P (drive pressure) and Qa (air consumption).
(3) Graph 3 shows correlation between P (drive pressure) and Pg (suction pressure; when the
sample gas inlet of the ejector is closed).
(4) Graph 4 shows correlation between P (drive pressure) and Qg (suction flow) for each gas pressure.