KOBOLD Instruments, Inc. 1801 Parkway View Drive, Pittsburgh PA 15205
Telephone: (412) 788-2830 · FAX: (412) 788-4890 www.koboldusa.com
Power Requirements:
Two Wire Switching:
24 to 240 VAC/VDC 50-60 Hz.
Three Wire Switching: 24 VDC
Solid State Switch Characteristics:
Max. Current:
500 mA.
Min. Current:
7.5 mA.
Leakage Current:
3 mA.
Voltage Drop:
4.5 Volts @ 500 mA.
10 Volts @ 7.5 mA.
Switching Delay:
Wet to Dry:
500 mSec.
Dry to Wet:
150 mSec.
Installation
1.) In order to ensure a leak-tight seal, a thread sealant such as
Teflon tape (or other appropriate thread sealant) should be used on
the probe threads prior to installation.
2.) The NQ must always be installed with the cable penetration facing
downward (between the 5 O’Clock to 7 O’Clock position) and creating
a drip loop with the cable. This will minimize the possibility of water
entering the cable gland thereby minimizing the possibility of water
migration into the electronics. After the unit is installed into the
process fitting, the housing may be rotated to achieve the proper
cable gland orientation.
Probe Orientation Installation Note:
To ensure reliable operation, the NQ-2000 must be installed into the
vessel with the forks of the sensing probe in the 3 O’Clock and 9
O’Clock position. This will minimze any air bubbles that could collect
in the gap and interfere with the acoustic coupling. The installation
nut on the NQ has a guide dot or drilling which can be used to ensure
that the probe is installed in the proper position (See Fig. 2).
Specifications
Series NQ Ultrasonic Level Switch
Installation/Operation Instructions
Description
KOBOLD’s Series NQ level switch is a compact, ultrasonic
gap level switch which is suited for use with low-viscosity,
non-coating liquids. The switch employs an ultrasonic
transmitter and receiver in the switch probe. When the probe
is immersed in liquid, the gap fills, resulting in the ultrasonic
transmitter being acoustically coupled to the receiver. This
acoustic coupling is sensed by a detection circuit and results
in the activation of the integral, solid-state switch. The solid-
state switch can be configured either as a two-wire or three-
wire controller. The unit is adjustable from a normally-open
to normally-closed (wet-on or dry-on) switch function via an
internal selector switch. Its solid-state design uses no
moving parts in the sensor or switch portions, making the
NQ level switch exceptionally reliable.
Fig. 2: Probe Orientation
The guide dot or drilling on the probe installation
nut should be located in the 12 O’Clock or 6 O’Clock
position to ensure that the probe is properly
oriented inside the tank.
(Bottom View)
Guide Dot
Fluid Temperature Range:
-40 to 2
50
°F
Max. Ambient Temp:
120°F with 25
0
°F Fluid
Max. Operating Pressure:
290
PSIG @-40 to
250
°F
Electrical Protection:
IP 65
