LumaSense Technologies M390 - Manual (Page 26)

M390 Manual Troubleshooting 26
9. Blackbody heats up and is glowing, but
the controller does not indicate temperature
> beginning of range. Check the M668 or M680 Infrared sensor
that is the primary sensing element for the
blackbody.
Set controller to about 20% power in
MANUAL mode.
Open rear door of M390. Is the LCD display
on the M668 (M680) on?
If Yes, go to step 10.
If No, check 24 VDC power to the M668 (or
M680).
10. M668 (or M680) displays backlights are
on and displays are indicating something.
Blackbody is in Auto, but still no
temperature indication on controller. Check that the M668 (M680) are indicating
temperature. Set the controller in manual
mode to about 20% power. Observe the
cavity by eye. When it starts glowing, check
the M668 (M680) display for indication of
temperature. If Yes, go to 11.
11. Does the M668 (M680) indicate the same
temperature as the controller (within a few
degrees)? If Yes, set the controller in AUTO mode. The
blackbody should begin to control
temperature.
If No, Check the 4-20 ma signal between the
M668 (M680) and the temperature
controller.
12. The M668 (M680) always displays
“UNDER” or “LOW” even when the
blackbody is glowing. Check the fiber optic cable between the
M668 (M680) and its lens assembly that is
mounted to view to the cavity rear.
On M668, use the Aiming Light (Key switch)
to see if light passes through the fiber and
out the lens assembly.
On M680, disconnect the fiber at the M680,
shine a light source into the fiber fiber and
out the lens assembly.
In either case, if there is no light
transmission, the fiber is broken.
13. M668 (M680) fiber is ok. Still reads
“UNDER” or “LOW”. Check that the lens assembly is aimed into
the blackbody body cavity. If yes, go to 14.
14. Aiming is OK. Still reads “UNDER” or
“LOW”. Aim a flashlight into the lens assembly while
observing the M668 (M680) display. If no
display activity, the M668 (M680) is faulty
and must be returned to LumaSense for
repair.