811-1005-E00 Datasheet, PDF (3/8 Pages) Magnetrol International, Inc. – Kotron® Model 811 RF Point Level Switch

TECHNOLOGY
The amount of capacitance developed in any vessel is
determined by the size (surface area) of the probe, the
distance from the probe to its ground, and the dielectric
of the medium being measured. Considering that the
probe’s mounting position is fixed and that the dielectric
value of the medium is constant, then the amount of
capacitance developed in any vessel becomes dependent
upon the amount of the probe which is covered by
the media.
As media rises and falls in the tank, the amount of
capacitance developed between the sensing probe and
the ground also rises and falls. This change in capaci-
tance is compared to the adjustable set point and
changes the state of a relay when they are equal.
SPECIFICATIONS
Supply voltage
120 VAC, 50–60 Hz (+10%, -15%)
240 VAC, 50–60 Hz (+10%, -15%)
24 VDC (±10%)
12 VDC (±10%)
Power consumption
120 or 240 VAC Less than 5 volt-amps
12 or 24 VDC 1 watt maximum
Zero range
0 pF minimum to 1000 pF maximum
Adjustable differential
0.5 to 700 pF
Output relays (DPDT) with gold flash contacts
AC 10 amp @ 120/240 VAC resistive
DC 10 amp @ 30 VDC resistive
DC 0.5 amp @ 125 VDC resistive
Response time
100 milliseconds
Repeatability
Better than 1.0%
Ambient temperature
Electronics -40° to +160° F (-40° to +70° C)
Operating process pressure/temperature
Dependent upon probe selection; refer to probe bulletin 50–125
Guarded probe 8XD-AAXA-0XX 3500 psig @ +100° F (240 bar @ +40° C)
Temperature coefficient of set point
-40° to +160° F (-40° to +70° C) ±.01% per degree F of setpoint
(±.018% per degree C of setpoint)
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