User Manual

IN 6/78-L Operating Manual Troubleshooting · 35
9 Troubleshooting
Before sending the pyrometer for repair, try to find the error and to solve the problem with the
help of the following list.
Temperature indication too low
· Incorrect alignment of the pyrometer with the object
Þ Realign to achieve the maximum temperature signal(see 3.3)
· Measuring object smaller than spot size
Þ check measuring distance, smallest spot size is at nominal measuring distance (see 3.4)
· Measuring object is not always in the measuring spot of the pyrometer
Þ Use maximum value storage (see 4.5)
· Emissivity set too high
Þ Set lower correct emissivity corresponding to the material (see 4.2)
· Lens contaminated
Þ Clean lens carefully (see 6.2)
Temperature indication too high
· Emissivity set too low
Þ Set lower correct emissivity corresponding to the material (see 4.2)
· The measurement is influenced by reflections of hot machine parts
Þ Use mechanical construction to avoid the influence of the interfering radiation
Measuring errors
· Indicated temperature is decreasing during the use of the pyrometer, contamination of the
lens
Þ Clean lens. Recommendation: use of air purge (see 3.3)
· Indicated temperature is decreasing during the use of the pyrometer, although the air purge
unit is used. Probably compressed air is not clean or air failed
Þ Clean the lens and use clean, dry and oil free compressed air
· Air contamination in the sighting path between pyrometer and object
Þ Change position of the pyrometer with a clean sighting path (if necessary use a ratio
pyrometer)
· RF-interferences
Þ Correct the connection of the cable shield (see 3.1)
· Instrument overheated
Þ Use cooling jacket with air or water cooling (see 2.5)
· Temperature Indication is fluctuating, probably caused by changing emissivity
Þ Wrong pyrometer type, use of ratio pyrometer recommended