KROHNE BM 100A Handbook - Manual (Page 52)

52 Handbook BM 100 A
6 Technical data
6.1 Technical Data
Input
Measured variable
Distance, level, liquid interface and volume
Measurement range Variable according to probe type, see Equipment architecture,
section 6.2
Blocking Distance Variable according to probe type, see Probe measurement limits
Output
Analogue
4 – 20 mA (3.8 – 20.5 mA according to NAMUR 043),
1 passive output (as standard)
Load
Active outputs 350 ohms maximum
Passive outputs (U-8)/22.10-3 ohms
Temperature drift <100 ppm / K
Resolution ± 3 µA
Digital HART
®
& KROHNE SMART protocols (as standard).
PROFIBUS-PA output also available on demand.
Error signal Status markers. NAMUR 043-compliant (output current values at
3.6 mA or 22mA according to value configured in fct. 1.3.2).
Performance Characteristics
Accuracy
Liquids when probe length, L < 6 m / 20 ft.*
± 5 mm / ± 0.2”
Optimised with appropriate on-site calibration
± 3 mm / ± 0.12”
Liquids when probe length, L >6 m / 20 ft.*
Additional error above 6m: ±0.02% of distance measured Level measurement
Solids (powders / granulates)**
± 20 mm / 0.79”
Interface measurement Liquids (with minimum layer of 100 mm / 4”)***
± 10 mm / 0.39” with configured and stable
ε
r
value
Repeatability ± 1 mm / ± 0.04”
Resolution ± 0.3 mm / ± 0.012”
Warm-up time 20 seconds to 1½ minutes (self-test before first reading)
* test medium: water ( ε
r
=80) ** test medium: cement ( ε
r
=3) *** test medium: oil ( ε
r
=2.4)
Test conditions
Ambient temperature
+20°C ±5°C / +70°F ±10°F
Ambient air pressure 1013 mbar abs. ±20 mbar / 14.69 psig ±0.29 psi
Relative air humidity 60% ±15%
Reference target coaxial probe: water surface
single probe: Ø0.8m (Ø31.5”) metal plate
twin probe: metal block “short circuit”
Distance from wall > 300 mm / 11.81” (not for coaxial probe)
Distance to obstruction > 1 m / > 3.28 ft.
Environment
Ambient temperature
-20 °C to + 50 °C / -4°F to 120°F
Storage temperature -40 °C to + 85°C / -40°F to 185°F
Protection IP 67 / NEMA 6 – 6P