Rosemount 755, Instruction Manual

Page: 35 / 94

I
NSTALLATION
748183-H
2-13
Rosemount Analytical
November 1997
CAUTION: HIGH PRESSURE SURGES
2.6.1 S
AMPLE
T
EMPERATURE
R
EQUIREMENTS
Sample temperature at the analyzer inlet should be in the range of 50
°
F to 150
°
F
(10
°
C to 66
°
C).
With a thoroughly dry sample, entry temperature can be as high as 150
°
F (66
°
C)
without affecting readout accuracy. Normally however a maximum entry temperature
of 110
°
F (43
°
C) is recommended so that the sample temperature will rise during
passage of the sample through the analyzer. This precaution ensures against cooling
of the sample and possible condensation of moisture. Such condensation should be
avoided as it may damage the detector.
2.6.2 S
AMPLE
P
RESSURE
R
EQUIREMENTS
: G
ENERAL
Operating pressure limits are as follows: Maximum, 10 psig (69 kPa gauge pressure);
minimum, 660 mm Hg absolute (88.1 kPa absolute pressure).
Operation outside the specified limits may damage the detector, and will void
the warranty.
The basic rule for pressure of sample and standard gases supplied to the inlet is to
calibrate the analyzer at the same pressure that will be used during subsequent
operation, and to maintain this pressure during operation. The arrangement required to
obtain appropriate pressure control will depend on the application. When inputting
sample or calibration gases, use the same pressure that will be used during
subsequent operation, refer to Section 2.6.3, Normal Operation at Positive Gauge
Pressures; or Section 2.6.4, Operation at Negative Gauge Pressure.
2.6.3 N
ORMAL
O
PERATION AT
P
OSITIVE
G
AUGE
P
RESSURES
P
RESSURE AT
S
AMPLE
I
NLET
Normally the sample is supplied to the analyzer inlet at a positive gauge pressure in
the range of 0 to 10 psig (0 to 69 kPa).
High pressure surges during admission of sample or standard gases can
damage the detector.
CAUTION: OPERATION LIMITS