Specifications - Chauvin Arnoux C.A 870 Notice De Fonctionnement

4.2 Precautions for measurement
If the surface to be measured is
as close as possible to the surface (less than 50 cm away)
(see § 4.3)
If the surface to be measured is covered in frost or other
particles, clean it so that the surface is clear before taking a
measurement.
If the surface to be measured is highly reflective, stick matt
tape or apply matt paint to the surface before measuring.
If the thermometer appears to be giving incorrect indications,
check the condition of the lens of the measuring orifice, since
it may be obscured by condensation or particles. If so, clean
it by carefully following the instructions in § 6.3 Upkeep.
4.3 Ratio between distance from target / diameter
of measurement field
This ratio, also called the field of vision, indicates the diameter
of the measurement field at a given distance from the target,
D/Ø = 10/1 (see figure below).
The minimum measurement distance is 150mm - this
gives a measurement spot diameter of 15mm.
In the case of small measurement points, it is important to
bring the probe sufficiently close to the target to avoid including
other points in the measurement field.
Diameter of measurement field
Ø 50
50
0
Distance from target

5. SPECIFICATIONS

Measurement range: -20 °C to +260°C (0° to 500°F)
Resolution: 1°C/°F
Polarity indication: automatic (- values only)
Adjustment of zero: automatic
Accuracy: ±2% of the reading or ±3°C/6°F (the highest) at an
≤
Ø 50 mm, hold the probe
Ø 200 mm
Ø 150
Ø 100
100 150
11
2 0 0
cm