KROHNE BM 102 Handbook - Manual (Page 70)

70 BM 102
5.2.3 Probe measurement limits
A1, the top dead zone,
The minimum distance from the flange to the
top limit of the measuring range. The
measurement displayed on the gauge will
freeze below this distance and status markers
will indicate that the reflection has been lost.
A2, the bottom dead zone,
A length at the end of the probe where
measurement is not possible. For products with
very low dielectric constants (
εr < 5), accuracy
may be affected in a non-linear zone up to
150 mm or 6” above the bottom dead zone, A2
D, the non measurement zone,
A zone where measurements cannot be taken
(i.e. the counterweight, turnbuckle, etc.*). The
measurement displayed on the gauge will
freeze to L
2
.
L
1
, factory configured probe length
Length to the end of the probe (excluding short
circuit or counterweight*). This parameter is
given in User Function 1.1.6: Probe length in
the User Configuration Mode.
L, with probe length
The length specified by the customer in the
order (including the counterweight).
Note : dead zone = blocking distance
*except the Ø12 mm x 100 mm or ؽ “ x 4” counterweight for the Ø8 mm or 0.3 “ single cable
probe
Warning:
Set PCSTAR 2 User Function 1.1.2 “Dead zone” in the gauge’s configuration mode
to at least top dead zone size as specified per probe type in the table below, so that
the gauge never displays product level within this zone. Refer to user function 1.1.2
in section 4.2 for more information.
Probe measurement limits
Probe type Top dead zone,
A1
εr = 80* Bottom dead
zone, A2
εr = 80* Top dead zone,
A1
εr = 2.4* Bottom dead
zone, A2
εr = 2.4*
Twin cable Ø4mm (4) 150mm or 6” 20mm or 0.8” 300 mm or 12” 100mm or 4”
Single cable Ø4mm (2) 300mm or 12” 20mm or 0.8” 400mm or 15¾” 100mm or 4”
Single rod (1) 300mm or 12” 20mm or 0.8” 400mm or 15¾” 100mm or 4”
Single cable Ø8mm (6) 300mm or 12” 20mm or 0.8” 400mm or 15¾” 100mm or 4”
Coaxial (3) 0mm or 0” 10mm or 0.4” 0mm or 0” 100mm or 4”
*The dielectric constant εr of water is 80. The dielectric constant εr of oil is 2.4
Note:
If the device is mounted on a tank fitting (e.g. a nozzle), include the height of the
tank fitting in the programmed dead zone.