Operating instructions
Conductivity measuring cells
type LF 1 FE, LFT 1 FE, LFT K1 FE, LF 1 DE,
LFT 1 DE, LFT K1 DE, LF 1
1
/
2
⬙
, LFT 1
1
/
2
⬙
, LFT K1
1
/
2
⬙
Description
The electrode cells type LF 1 FE, LFT 1 FE, LFT K1 FE, LF 1 DE, LFT 1 DE,
LFT K1 DE, LF 1
1
/
2
⬙
, LFT 1
1
/
2
⬙
, LFT K1
1
/
2
⬙
with PG 13.5 or
1
/
2
⬙
screwed thread as well as
with or without integrated Pt 100/1000 for temperature compensation serve the
conductive measurement of the electrolytic conductivity in aqueous media. The sensors
are designed either with fixed cable (designation ... FE) or with DIN 4P right-angle plug
(designation ... DE). The instrument is connected to a measuring device via a 2- or
4-wire instrument lead.
IMPORTANT
The measuring cell must be placed in distilled or demineralized water for
5 - 10 minutes prior to initial operation.
For correct measurement, particular care must be taken to ensure that no
air bubbles remain in the gap (i.e. between the measurement electrodes).
Servicing/cleaning
Operation of the sensor should be checked regularly and the sensor is to be calibrated
as required. The gap between the measuring electrodes must be checked regularly for
dirt deposits. Any adhering deposits can be removed with the aid of a soft water jet, by
immersion for 2 - 3 minutes in diluted (1% solution) acid or by wiping with a cloth or soft
brush (e.g. toothbrush/bottle brush).
Storage
Dry
Installation
For installation into the flow meter type DLG (1
⬙
boring), an adapter PG 13.5/1
⬙
(parts
number 1002190) is required!
Particular care must be taken during installation to ensure that the measuring electrodes
are always completely covered with liquid medium.
IMPORTANT
Because of their material, the measuring cells are not suitable for
measurement of surfactant-containing cleaning agents and solvent-
containing media.
Technical Data
Cell constant:
k = 1.0 cm
-1
(
±
5 %)
Measuring range:
approx. 0.01 ... 20 mS/cm
Medium temperature:
0...80
°
C (unpressurized)
Max. pressure:
16 bar (at 25
°
C)
Thread:
PG 13.5 or
1
/
2
⬙
Dimensions:
Stem length
(up to push-and-twist connector)
120 mm; ø 12 mm
Storage temperature:
-5...50
°
C
Electrodes:
Special graphite
Temperature sensor:
Pt 100 or Pt 1000
(integrated in cell stem)
in type LFT/LFT K
Cell stem:
Epoxy
Electrical connection
to sensor:
fixed cable 5 m, types ... FE
DIN 4P right-angle plug,
types ... DE
Electrical connection
to measuring instrument: 2- or 4-wire instrument lead
type of enclosure IP 65
Pin Assignments
white/brown: Electrodes
green/yellow: Pt 100/Pt 1000
DIN plug connection: electrodes
+2, Pt 100/Pt 1000 1+3
120
±
3
Ø 12 mm
120
pk_6_085
pk_6_086
Ø 12 mm
BA_DT_079_09_06_G_GB_F_E.p65
20.09.2006, 11:35 Uhr
2