KROHNE BM 100A Handbook - Manual (Page 57)

Handbook BM 100 A 57
6.2.3 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 (
ε
r
< 5), accuracy
may be affected in a non-linear zone up to 150
mm / 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. –
except the Ø12 mm x 100 mm counterweight
for the type K single cable Ø8 mm probe). The
measurement displayed on the gauge will
freeze to L
1
.
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 1.1.7 in the
Configuration Mode.
L, Probe length
The length specified by the customer in the
order.
Warning:
Set User Function 1.1.2 “Hold Distance” 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 3.4.5
for more information.
Probe measurement limits
Probe type Top dead
zone, A1
ε
r
= 80*
Bottom dead
zone, A2
ε
r
= 80*
Top dead
zone, A1
ε
r
= 2.4*
Bottom dead
zone, A2
ε
r
= 2.4*
Twin rod (A) 250 mm / 9.8” 20 mm / 0.8” 330 mm / 13” 100 mm / 3.9”
Twin cable
Ø6 mm (B) 250 mm / 9.8” 20 mm / 0.8” 330 mm / 13” 100 mm / 3.9”
Twin cable
Ø4 mm (L) 250 mm / 9.8” 20 mm / 0.8” 330 mm / 13” 100 mm / 3.9”
Coaxial (D) 0 mm / 0” (**) 10 mm / 0.4” 0 mm / 0” (***) 100 mm / 3.9”
Single rod (F) 400 mm / 15¾” 20 mm / 0.8” 500 mm / 19.7” 100 mm / 3.9”
Reverse(G) 50 mm / 2” 250 mm / 9.8” N/a N/a
Single cable Ø4 mm (H) 400 mm / 15¾” 20mm / 0.8” 500 mm / 19.7” 100 mm / 3.9”
Single cable Ø8 mm (K) 400 mm / 15¾” 20 mm / 0.8” 500 mm / 19.7” 100 mm / 3.9”
*The dielectric constant, ε
r
, of water is 80. The dielectric constant, ε
r
, of oil is 2.4.
** 20 mm / 0.8” for Ex version. *** 50mm / 2” for Ex version.