Velleman DVM8861 - Manual (Page 7)

DVM8861
00 (16/10/2008)
7
polished surfaces will be inaccurate. Use some masking tape or paint to compensate,
allow sufficient time for the tape or paint to reach the surface temperature.
Substance Emissivity Substance Emissivity
Asphalt 0.90 to 0.98 Cloth (black) 0.98
Concrete 0.94 Human skin 0.98
Cement 0.96 Leather 0.95 to 1.00
Sand 0.90 Charcoal (powder) 0.96
Earth 0.92 to 0.96 Lacquer 0.80 to 0.95
Water 0.92 to 0.96 Lacquer (matt) 0.97
Ice 0.96 to 0.98 Rubber (black) 0.94
Snow 0.83 Plastic 0.85 to 0.95
Glass 0.90 to 0.95 Timber 0.90
Ceramic 0.90 to 0.94 Paper 0.70 to 0.94
Marble 0.94 Chromium oxides 0.81
Plaster 0.80 to 0.90 Copper oxides 0.78
Mortar 0.89 to 0.91 Iron oxides 0.78 to 0.82
Brick 0.93 to 0.96 Textiles 0.90
Field of view
The target must be larger than the spot size to ensure correct measurement. This
means that for smaller targets, the thermometer must be held closer to the target. For
best accuracy, make sure the target is at least twice as large as the spot size.
7. Troubleshooting
LCD display doesn’t light up
when the measurements
trigger is pulled.
Possibly a battery problem. Check and replace the
battery.
The measured temperature
changes very quickly and the
shown value seems unlikely.
Check the emissivity value. When set too low,
inaccurate readings will result.
Display shows
Over range indication, measured temperature is too
high or too low. See specifications for temperature
range.
•
Repairs or service should only be carried out by qualified and trained technicians.
8. Cleaning and storage
• The IR sensor (1) is the most delicate part of the thermometer and should be kept
clean at all times.
• To do this, only use a soft cloth or cotton bud. Do not use excessive pressure
on the sensor.
• Wipe the other parts of the thermometer regularly with a dry cloth. Do not use
abrasive solutions or solvents.
• Do not submerge the thermometer in water or any other liquid.
• There are no user-serviceable parts.
• Contact your dealer for spare parts if necessary.
• The device must be stored in a place with temperature conditions between 10°C and
+60°C (+14°F and +140°F) and relative humidity lower than 80%.