- Omega Engineering, Inc. Non-Intrusive Capacitance Switch User's Guide
Step One
SPECIFICATIONS
Technology:
The non-intrusive RF capacitance switch detects the pres-
ence of liquid or air by measuring the conductive or dielec-
tric values which are present in all materials. An electrical
capacitor is formed between the level switch and the outer
tank wall. As liquid rises and falls against the inner wall, the
capacitance effect is greatly increased and the 1A SPST
relay changes state.
1.7"(44mm)
2.8"(71mm)
3.2"(81mm)
8’ Cable (2.5m)
(+)
(-)
NO/NC
COM
Shld
Red
RELAY
Black
White
Green
1.0"
(25mm)
1.6"(41mm)
2.2"(56mm)
100
80
60
40
20
00
-20
12 16 20 24 28 32 36
Acceptable
Range
Unacceptable
Range
Maximum Tem. / Voltage Derating
Continuous 20 mA Sinking Curve
Ambient Sensor Temperature (¡C)
Operating Voltage (VDC)
1,600
1,400
1,200
1,000
800
600
400
200
0
12 18 24 30 36
Acceptable
Range
Unacceptable
Range
4-20 mA Sensor
Electrical Loading Limits
Max. Series Resistance (Ohms)
Supply Voltage (VDC)
Tank mounting:
Tank mat. comp.:
Tank wall thick.:
Accuracy:
Repeatability:
Dielectric range:
Conductive range:
Supply voltage:
Consumption:
Contact type:
Contact rating:
Contact output:
Process temp.:
Enclosure rating:
Enclosure mat.:
Conduit entrance:
Bracket material:
Bracket mounting:
Cable jacket mat.:
Cable type:
Cable length:
Classification:
CE compliance:
Non-intrusive
Non-metallic
< 1" (25 mm)
±
1 mm in water
±
0.5 mm in water
> 10 constants
> 100 micromhos
12-36 VDC
25 mA maximum
(1) SPST relay
120 VAC/VDC @ 1A
(CE: 60 VAC/VDC @ 1A)
Selectable NO/NC
F: -40˚ to 194˚
C: -40˚ to 90˚
NEMA 4X (IP65)
PSO
Single, 1/2" NPT
PE
3M adhesive / plastic
thermal weld
PP
4-conductor, #22 AWG
(shielded)
Standard: 10' (3m)
General purpose
EN 50082-2 immunity
EN 55011 emission
EN 61010-1 safety
Acetone 21
Acetoaldehyde 22.2
Acetyl methyl hexyl
ketone 28
Alcohol 16 to 31
Ammonia 15 to 25
Acetic acid 4.1 to 6.2
Butyl chloride 9.6
Barium chloride 9 to 11
Benzene 2.3
Benzine 2.3
Barium nitrate 5.6
Bromine 3.1
Chlorobenzene 4.7 to 6
Chlorotoluene 4.7
Chloroform 4.5 to 5.0
Chlorine, liquid 2.0
Carbon tetrachloride 2.2
Cyan 2.6
Cyclohexanemethanol 3.7
D.I. Water 20
Ethyl toluene 2.2
Ethyl alcohol 23
Ethylene glycol 37
Ethylene oxide 14
Ethylene dichloride
11 to 17
Ethylene chloride 10.5
Ethyl acetate 6.4
Ethyl salicylate 8.6
Ethyl stearate 2.9
Ethyl silicote 4.1
Formic acid 59
Ferric oleate 2.6
Freon 2.2
Glycerine 47
Glycol 30
Glycol nitrite 27
Gasoline 2 to 2.2
Hydrochloric acid 4.6
Isobutyric acid 2.7
Isobutyl methyl ketone 13
Jet fuel 1.7
Lead carbonate 18
Lead nitrate 38
Methyl salicylate 9.0
Methanol 33
Methyl alcohol 33 to 38
Margarine,liquid 2.8 to 3.2
Methyl acetate 7.3
N-butyl formate 2.4
Nitrobenzene 26 to 35
Nitrotoluene 25
Naphthalene 2.3 to 2.5
Oils, vegetable 2.5 to 3.5
Oils, mineral 2.3 to 2.4
Oils, petroleum 1.8 to 2.2
Oleic acid 2.5
Propane, liquid 1.8 to 1.9
Potassium nitrate
5.0 to 5.9
Potassium chloride 5.0
Stearic acid 2.3
Toluene 2.4
Trichloroethylene 3.4
Trichloroacetic acid 4.5
Terephthalic acid
1.5 to 1.7
Thinner 3.7
Urea 3.5
Vinyl chloride 2.8 to 6
Vinyl alcohol 1.8 to 2.0
Water, 20°C 80
Water, 100°C 48
Table of Common Dielectric Constants:
NOTE: Liquids with a conductivity value > 100 µU are fine if coating is not an issue. Liquids with a dielectric constant less than 20 may not be reli-
ably detected by an LVP-51 series level switch, depending on conditions.