Micromeritics 1305 Operator's Manual page 28

Controls and Components
Overpressure Relief
Valve
Filter
Gas inlet and
Gas outlet/vacuum
connection
Power entrance
3-6
Model 1305 MultiVolume Pycnometer
Provided for protection against damage to the instru-
ment. The overpressure relief valve is connected di-
rectly at the gas input connection and is set at the
factory to open when the pressure reaches 25 ±1 psig.
The setting is altered by means of a set screw at its
discharge end. The setting should be changed only if
an accurate pressure gauge is available and the relief
point is known to be incorrect. Resealing of this
valve requires that the gas inlet pressure be reduced
to under 20 psig before leaking will stop.
The filter is a large area, fritted metal disk installed
just downstream of the sample chamber. Its function
is to protect the transducer, valves, and expansion vol-
umes against contamination by powder particles
which could cause leaks, volume changes, and pres-
sure instability. It is mounted on the rear wall of the
plumbing compartment in a cylindrical assembly. The
filter should be cleaned or replaced only after confirm-
ing that powder has been drawn into the system. A
spare filter is included in the accessory kit.
The gas inlet is a 1/4-in. diameter threaded brass con-
nection designed to accept 1/8-in. metal tubing se-
®
cured by a Swagelok fitting with brass ferrules.
The gas outlet/vacuum connection is a 0.300-in. di-
ameter brass barbed fitting intended for use with
0.250-in. inside diameter rubber or plastic tub-
ing. Both fittings are located on the righthand side of
the instrument near the power entrance. The gas out-
let/vacuum connection is closest to the front of the in-
strument.
Power enters the instrument through this assembly lo-
cated on the righthand side of the instrument. An inter-
national power connector of the IEC-type is included
and requires a detachable power cord which is in-
cluded in the accessory kit.
A small circuit card permits selection of any operating
voltage. A built-in fuse provides protection; the fuse
should be a 0.5 Ampere slow-blow type for voltages
of 100 to 120 volts and a 0.25 Ampere slow-blow
type for 200 to 240 volts. Refer to Chapter 2 for in-
structions on voltage selection and fusing.
Jun 99