L--740--28--E
1
10.6.7 Maintenance and checking
In order to use OVAL
’
s Coriolis Flowmeters for long period of time, please perform inspection and
maintenance according to the following items. Also, make sure to check and inspect the Flowmeter while
de-energizing without hazardous gas in the surrounding area.
Check item
Description
Check
General
Is the dedicated cable being used ?
If it is having a mixed touch with other cables, particularly with power supply
lines ?
If the coating is damaged or peeling off ?
Is the dedicated cable properly connected ?
Is the terminal end properly treated ?
Is the separation cover installed ?
Is the lid for the terminal box installed ?
Are bolts and hex socket set screws for fastening the transmitter loose ?
Grounding
Is the grounding made properly ?
Is the screw for the grounding terminal loose ?
If the grounding wires are deteriorated ?
Sensor
Drive circuit resistance: Resistance range: 50 to 5k
Ω
*1
Pick-off circuit resistance: Resistance range: 60 to 600
Ω
*1
Temp. sensor circuit resistance: (100+0.385
×
Temp.)
Ω
*1: There are some differences depending on each sensor and fluid temp.
*2: This measurement is possible only with the separate type. If measured at
the transmitter side, the interconnection resistance of dedicated cable is
added.
Transmitter
If any of the connections of display lid, terminal lid or side lid are loose ?
If the part tightened up of cable gland loose ?
Is the packing of the cable gland discolored, hardened, torn, or cracked ?
Is the enclosure and glass deformed or has crack or such ?
*Paint is not regarded to be enclosure.
About handling of grease on bonded surfaces:
If short and deterioration of the grease on the parts below are found through normal use, replenish grease
properly. For this purpose, periodic check is recommended.
Parts screw used: Terminal box – lid (separately mounted only)