pressure drop across the orifice is measured by a Manometer, in which the scale is
calibrated in units of flow (m3/min). In the APM 460 PUF Sampler, the Manometer
Assembly is placed in the upper portion of the front panel assembly so that it is
convenient to read, and a reflecting tube support has been added to minimize parallax
error.
The glass tube containing the PUF cartridge is placed in a Teflon lined holder
immediately below the Filter Adaptor assembly. Suitable seal rings have been
incorporated at each joint to ensure a leak tight assembly.
MAIN PARTS AND CONTROLS
√
Refer
to figure 1 and 2 to locate the controls and parts described in this
section.
Mains Input and its Fuse
: The APM 460 PUF sampler requires 220 Volts AC
single phase, 50 Hz AC mains supply for operation. Mains power is
connected to the system through a three pin IEC socket provided at
the back of the instrument. An appropriate chord is provided with the
instrument. Use only a three pin AC mains socket so that earth /
ground connection of the instrument cabinet is maintained. A neon
indicator has also been provided to indicate the mains supply. An
over current cutoff has been provided to protect the system. If the
current protection trips off, you have to press the RED reset button
on the instrument panel.
CAUTION: Do check the reason for over-
current tripping before re-starting the operation.
Power on/off switch :
This DPST toggle switch is used to control the AC mains
power coming to the instrument.
Time Totalizer
: The Time Totalizer is wired to operate only if the Blower, drawing
air through the sampler, is in operation. Therefore it records the
actual duration of each sample and can also be utilized to keep track
of preventive maintenance schedules of the instrument.
Digital Timer
: The Timer is provided to shut off the instrument after pre set time.
The Digital Timer provided in APM 460PUF allows a user to
automatically control ON/OFF cycles. The equipment will
automatically start up or shutdown as per the program fed into the
timer. Details of operation of the timer are given in Chapter IV
Voltage Stabilizer
: A voltage stabilizer is fitted in the instrument to control
supplies of input power within acceptable range 230
+
10V. The
Stabilizer has 4 step input voltage control to give indicated out put