Kahn HygroPort I.S., Руководство пользователя

Страница: 19 / 70

HygroPort I.S. User’s Manual
2.4 Instrument Start-Up
When turned on, the instrument goes through an initialization process of between 4
and 7 minutes, depending on the sensor and sample gas characteristics, during which
time the internal sensor is heated to a maximum of 140°F (60ºC). The heating
process excites the moisture molecules already present in the sensor and accelerates
equilibration with the moisture content of the sample gas. During this period the
sample gas flow purges the system. After this period, the sensor will be dried to
below the dewpoint of the gas to be measured. The heating is then switched off and
the display flashes.
Figure 2.4 shows a typical start-up sequence.
When turned on, the System Initializing screen is displayed for a period of
approximately f ive seconds; following which the Initialization screen is displayed for a
period of 1 minute. Thereafter the screen will show a countdown time of the
remaining initialization time.
During this period, gas will be flowing through the sensor and can be externally regulated
to meet the instrument’s fl low requirements. The real time sensor temperature is
indicated in the secondary display area. The Initializing icon (item 6 in
Figure 2.3) is
displayed in the status area. The keyboard, with the exception of the scroll up and
scroll down keys, is locked out, as indicated by the keyboard lock icon (item 4 in
Figure
2.3), until the initialization period has expired. Note that it is possible to terminate the
initialization process before the initialization period has timed out by pressing the scroll
up and scroll down keys simultaneously. This action aborts the instrument’s response
enhancement system but allows the operator to make an immediate measurement if
the measured dewpoint is wetter than –4°F (-20ºC) dewpoint.
While the initialization process is in progress, the backlight time-out is precluded and,
if any external transmitter has been configured and connected to the instrument,
display of the external transmitter reading is also precluded. After the end of the
initialization period, the display reverts to the measurement mode displaying the
dewpoint (in the currently selected unit) in the primary display area, and any external
transmitter reading in the secondary display area. By default, the internal temperature
is displayed in the secondary display area if no external transmitter is configured.
When the reading has been acquired, and the instrument has been dynamically
tracking it for a given period, a message, Measurement OK, indicates that the
instrument is stable and reading within 0.9°F (0.5°C) for two minutes.
Issue 6, December 2019 8 Kahn Instruments