Det-Tronics UD10 DCU Emulator FlexVu Universal Display Unit - Manual (Page 61)

4.2 95-8656 L-4
cAlibrAtion
To initiate calibration of the CGS sensor from the
UD10-DCU Display:
1. Using the magnet to activate the switches on the
UD10-DCU display, navigate to the “Calibrate”
menu.
2. Activate “Execute” (Enter/Select) to start calibration.
3. The UD10-DCU will display “Waiting for Zero” on the
main display screen as it performs zero calibration.
4. When zero calibration is complete, the UD10-DCU
will display “Waiting for Gas” on the screen.
5. Apply calibration gas to the sensor.
6. The UD10-DCU will display “Waiting for Span”
on the screen while the span calibration is being
performed.
7. When the UD10-DCU shows “Remove Cal Gas”
on the screen, remove the calibration gas from the
sensor.
8. The UD10-DCU automatically exits the Calibrate
mode and returns to normal operating mode upon
completion of a successful calibration.
Determining Sensor Life Remaining
At the time of calibration, the UD10 logs the sensor
mV signal. This value can be used for determining the
approximate sensor life remaining.
To view all the recorded mV signal values for the sensor,
from the Main Menu, navigate to:
Device Status > Calibration Log > Span.
To view the mV signal from the most recent calibration
only, from the Main Menu, navigate to:
Device Status > Device Info > Response.
A typical new sensor reads between 45 and 55 mV.
• At 21-55 mV, "Cal OK" is recorded in the Cal Log,
along with the Span value.
• At 15-20 mV, "Cal OK" is recorded in the Cal Log,
along with the Span value. In addition, "Weak Sensor"
is shown on the UD10 display for about 20 seconds.
After 20 seconds, the "Weak Sensor" message is no
longer seen, but a "Weak Sensor" status is recorded
(Device Status > Fault/Status > Status).
• At 14 mV or less, "Weak Sensor" is shown on the
UD10 display for about 20 seconds, then a Cal Fault
is shown. The Cal Log shows "Cal Fail" with a Span
value of 0.00 mV.
K fActor
If the system will be detecting a gas/vapor other than the
gas used in the actual calibration process, a conversion
K-Factor must be used. The K-Factor can be entered
prior to calibration by navigating to the “Device Option”
menu.
Main Menu
Process Vars
Display Status
Device Status
Display Setup
Device Setup
Device Cal
Display Test
Device Setup
Device Option
Device Option
Gas Name
K-Factor
The UD10-DCU communicates the K-Factor to the
CGS Interface Board during the calibration process,
where the proper correction is made to ensure accurate
calibration.
The actual effect of the K-Factor can be observed
as the span portion of the calibration is completed.
For example, suppose a K-Factor of 0.865 has been
programmed. When calibration is performed, the
UD10-DCU will display 50% as span is accepted. It
will then apply the K-Factor, and the displayed value will
change to 43.3% LFL.
For additional information regarding K-Factors,
including a list of K-Factors for many common gases,
refer to Technical Bulletin number 76-1017.
menu structure
UD10-DCU with CgS Series Sensor
Refer to the following menu when using the UD10-DCU’s
LCD display and internal magnetic switches.
menu HeLp
Status menus only allow the user to view the data.
The Setup menus allow the user to both view and
edit the data.
Main Menu
Process Vars
Display Status
Device Status
Display Setup
Device Setup
Device Cal
Display Test
Device Cal
Calibration
Cal Gas
Cal Gas Conc
K Factor
Calibration
Execute