Emerson 20/20 User Manual

Page of 120
13 – 1
Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 1.8.5153
Section 13 • Instruments Calibration
Overview
The Instrument Calibration screen allows the operator 
to defi ne how the Vission 20/20 will interpret the signal 
from any devices attached to the panel’s analog inputs. 
The instrument calibration screen is organized up to six 
pages. Each page is then divided into several left side 
selected tabs. Each tab will be headed with an informa-
tion bar labeled “I/O” that give the basic information 
for that device. The “A/D bit Value” display box shows 
the unmodifi ed value read by the Vission 20/20 analog 
to digital converters. This display box is not affected by 
any changes to the calibrations settings. As long as a de-
vice is connected to the associated input, there will be 
a value in this display box. The “Calibrated Value” dis-
play box shows the end result of the calibration process. 
Therefore, any changes to the calibration setpoint will 
effect what value is shown, see Figure 13-1 Instruments 
Calibration Screen. 
All instruments are calibrated using a two point linear 
calibration process. Any device that has a non-linear re-
sponse to environmental stimuli will not be able to be 
calibrated through the Vission 20/20.
Pressure and Temperature Inputs
The most commonly used instruments are tempera-
ture and pressure sensors. The fi rst two pages of the 
Instrument Calibration screen are dedicated to these 
instruments. 
Each tab on these two pages are divided into two sec-
tions, Device Calibration and Channel Calibration. The 
device calibration section is where the operation param-
eters of the instrument is defi ned. The channel calibra-
tion defi nes the type of signal sent by the instrument.
Default Devices:
•  By selecting this option, the operator will have access 
via a drop-down box of several common devices. The 
Figure 13-1. Instruments Calibration Screen