Fluke RUSKA 7252, Руководство пользователя

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Theory of Operation
Software
2
2-13
50
o
C. The Duty Cycle indicates the amount of time (in units of percentage) that the oven
control is turned on in order to maintain the oven at the proper set-point of 50
o
C. A unit
that is operating properly, after it has fully warmed up, should indicate a sensor
temperature of 50
o
C and a duty cycle between 10% to 90%.
If operating the instrument in a very cold environment and the oven duty cycle is at a
high percentage (>90%) you will need to turn the fan off. If you are operating in a warm
environment or when multiple systems are housed in consoles without adequate
ventilation, the system may become too hot and generate the oven control failure error
message. If operating the instrument in a warm environment and the oven duty cycle is at
a low percentage (>10%) you will need to turn the fan on. See Chapter 6, Fan Operation.
When the operator changes the status of the fan, it will remain in that condition until the
operator changes the setting.
glb42.bmp
Figure 2-7. Menu | Menu | Display | Temp Screen
Pressure Reading and Correction
The sensor’s analog output is processed by an analog-to-digital circuit that results in an
output referred to as counts . This output is corrected for the applied effects listed below.
The counts are linearized and the resulting pressure value is corrected for the variations in
head pressure, vacuum, case effect, and oven temperature effects.
The following equations are used by the control algorithm to adjust and correct the
pressure signal.
Zero Coefficients
CsH Zero correction for High FSR (Full-Scale Resistors) Value is in counts
(7,381,975 = full scale of current sensor).
CsL Zero correction for Low FSR. Value is in counts (7,381,975 = full scale of low
FSR)
HsZ Hardware zero correction. (0 to 4095, center is 2048).
SsZ Zero corrections scaling factor. Ratio of High FSR to Low FSR. Used only
when Case Effect Coefficient or Oven Temperature Coefficient are non-zero.
s=0 for high range sensor, s=1 for low range sensor.