Edgetech 2000 Series - Recommended Hardware and Flow Rate Adjustments

\
"
Model2000 Series DewPrime
Dew Point Hygrometers
---------- Installation Procedures
the degree of permanenc y of the installation , and the type
of fittings and connections to be used. Generally, stain-
less steel is preferre d for pennanent installations operat-
ingat lo w dew points. O n stainless steel lines , either
swage or flare-type fittings can be used. Leaks in the
0
-10
-20
-30
1 \
"-..
........_
\\ '\.
\
N
-
YLO
-
N
--
sampling system must be avoided , particularl y for
,-
installations operating below atmospheric pressures , since
leakage of ambient air into the sampling system will
.
LL.
-40
L
,...:
-45
z
-50
5
·55
1 ..
COPPER
seriously offset the reading s obtained.
D..
-60
\\
\
\
"
.....
"
..............
w
-65
2.11 MATERIAL MOISTURE PROPERTIES
All material s will absorb moisture to some extent. The
c
-70
·75
-80
N "'-... ' . -.
_\
\.. \. ............ OLYETHYL
-
E
-
N ---
adjacent curves shown in Figure 2-2 relate typical
-85
-90
"'"
. TEFLON
desorptio n propertie s of commonsampling linematerials
after being exposed to a "wet'' ga s such as the ambient
atmosphere.The curve s illustrate the difficulty of obtain-
r· ing a fast system response whe n switching from a high
dew point sample to a low dew point sample . Even . i f the
instrument were to respond in.stmtly , the sampling lines
would dictate the overall response.
2.12 SELECI'ION OF SAMPLING PUMPS
Three types of pumps are generally suitable for hygro-
-95
-100
NICKEL
S:AJ STEE ,
I
20 60 100 140 1110 220 260 300
TIME. MINUTES
Figure 2-2. Typical sampleline
material response characteristics.
metric work. For iDstallations where the sample is not to
b e returned to the process, the Ga s Manufacturing Co.
vane pump is acceptable. This pump offer s a reasonably
high degree of reliabilit y and can handle large volumes of
air . The vane type of pum p tends to contaminate the
sample with minute amounts of pump-wea r by-products
2.13 RECOMMENDED HARDWARE
2.13.1 Pumps
Cazbo n Vane Type Gast Mfg.Co.Model
0531-102B-347X (0 . 6 cfm)
orequivalent
(iron, carbon); therefore , it should be used on the output
side of the Sensor .
For general-purpose use or for closed-loop sampling at
atmospheric pressure, any one of several types of dia-
phragm pumps, such as the Neptune Dynapump,can be
used. The Dynapump uses a neoprene diaphragm, and the
Diaphragm
BellowsType
Dynapump-Neptune
Products,
Model2 (2.25 cu. inlmin.)
or equivalent
Meta l Bellow s Co.MB-21
or equivalent.
pmnp housing is aluminum.
2.13.2 Filters (General Purpose, In-Line)
For most closed-loop sampling,where leak tightnes s is
essential , the welded bellows type, such as the Metal
Bellow s MB-2 1 , can be used. These pump s are available
fro m EdgeTech as well as from thei r respective manufac-
turers.(The optional Sample System Kit uses the Nep-
tune Dynapum p Model No.2.)
Stainless Steel
Brass
NUPRO 4F-316, with 60-
micron filter element or
equivalent
NUPRO 4F, with 60-micron
filter element or equivalent.