GDS C1, Инструкция по эксплуатации

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2.2.7 CAL MODE
IMPORTANT! Each channel’s
CALIBRATION
menu is inactive unless it’s Input
Data From: menu, described in section 2.2.4, is set for Analog with Local Cal or Sensor
Direct . C1 CAL MODE features allow pushbutton calibration of zero and span values.
This feature should be utilized only when there are no other zero/span controls within the
monitoring system since it is inappropriate to calibrate a signal at more than one point.
Therefore, if calibration is to be performed at another transmitter or monitoring device,
the C1 CAL MODE feature should not be used.
The CALIBRATION MENU allows entering the correct
Cal ZERO
&
Cal SPAN
set-
point values needed to calibrate the sensor. These are entered in the same engineering
units as input range.
Set Zero & Set Span
controls in this menu allow pushbutton
calibration by moving the pointer to each and pressing the EDIT key. A live reading of
the channel’s value allows calibration checks to see if an adjustment is needed.
Unintentional calibrations are reset by the
Unity Gain menu item. Unity Gain resets
zero offset to 0 and span gain to 1. It is useful for returning the calibration to a known
starting place. Sensor aging may be monitored by recording zero and span readings at
Unity Gain when it is new, and again at later dates when degradation may have
occurred.
To check zero calibration, apply the ZERO calibration value to the sensor and observe
the live reading. If the zero reading differs from the zero setpoint, a calibration is needed.
To calibrate zero, move the pointer to
Set Zero and press EDIT . A warning message
explains that pressing EDIT again will change the zero calibration and any other key will
exit. The procedure for span calibration is identical. For example, if an LEL combustible
sensor is to be spanned with 50% LEL span gas, the span set-point must be 50%. If 45%
LEL is to be used later, the span set-point must be changed to 45% to match the span
calibration gas. If the reading is only 40% LEL with the 50% gas applied a span
calibration is needed. Move the pointer to the
Set Span
entry and press EDIT twice.
Unity Gain may be used at anytime to cancel incorrect calibrations and start again.
Figure 2.9