Det-Tronics UD10 FlexVu Explosion-Proof Universal Display Unit - Manual (Page 67)

4.2 95-8661 M-4
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, then selecting “K-Factor”. Enter
the desired K-Factor and activate the “Enter” button.
The new K-Factor will be applied when the sensor is
calibrated.
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 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 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 with CgS Series Sensor
Refer to the following menu when using the UD10’s
LCD display and internal magnetic switches.
When connecting a HART Communicator to the UD10’s
4-20 mA output, refer to the “UD10 HART” menu in
Appendix E.
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.