DH Instruments PPCH-G, Руководство по эксплуатации и обслуживанию

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3. OPERATION
Page 39 © 2007 DH Instruments, a Fluke Company
Before operating PPCH-G with external Q-RPTs, check carefully that the Q-RPT TEST(+) port
is connected to the PPCH-G TEST port. If the external Q-RPT is NOT connected to the PPCH-G
TEST port, it will not measure the pressure generated by PPCH-G and PPCH-G may reach a
pressure higher than the target pressure before its watchdog function recognizes that the
external RPT is not connected.
Take care not to overpressure external Q-RPTs when using them with a PPCH-G. When using
external Q-RPTs in RPM4s as reference pressure measurement devices with a PPCH-G, the user is
responsible to setting up hardware and following procedures to protect lower range Q-RPTs from
overpressure. Only the Lo Q-RPT (IL) built-into the PPCH-G is protected automatically.
To verify or confirm the active range from the MAIN RUN screen, use [+/-] or [RANGE] to
view the active range description (see Section 3.3.1).
See Table 7 for a listing of all selections and settings affected by AutoRange and their
default values.
3.3.5 [RPT]
 PURPOSE
Search for, initialize and display internal and external Q-RPTs available to the PPCH-G system.
 PRINCIPLE
Up to four Q-RPTs can be included in a PPCH-G pressure controller/calibrator system, two internal
and two external (see Section 3.2.5). PPCH-G communicates with external Q-RPTs by RS232
over its COM2 port.
To be available for use by the PPCH-G system, external Q-RPTs must be identified and
initialized. A Q-RPT search function occurs automatically each time PPCH-G power is
cycled. Also, pressing
[RPT]
initiates the Q-RPT search and allows the Q-RPTs that are
available to PPCH-G to be viewed. Use
[RPT]
to update the PPCH-G system configuration if
you connect and disconnect Q-RPTs without cycling PPCH-G power.
See Sections 3.2.6, 2.3.7.1 for information on hooking up external Q-RPTs to a PPCH-G system.
Before operating PPCH-G with external Q-RPTs, check carefully that the Q-RPT TEST(+) port
is connected to the PPCH-G TEST port. If the external Q-RPT is NOT connected to the PPCH-G TEST
port, it will not measure the pressure generated by PPCH-G and PPCH-G may reach a pressure higher
than the target pressure before its watchdog function recognizes that the external RPT is not
connected.
Take care not to overpressure external Q-RPTs when using them with a PPCH-G. When using
external Q-RPTs in RPM4s as reference pressure measurement devices with a PPCH-G, the user is
responsible to setting up hardware and following procedures to protect lower range Q-RPTs from
overpressure. Only the Lo Q-RPT (IL) built-into the PPCH-G is protected automatically.