35
58-603 Pulsar
®
Model R86 Radar Transmitter
3.0 Reference Information
This section presents an overview of the operation of the
PULSAR Model R86 Radar Level Transmitter, information
on troubleshooting, common problems, listings of agency
approvals, lists of replacement and recommended spare
parts, and detailed physical, functional and performance
specifications.
3.1 Description
The PULSAR Model R86 is a two-wire, 24 VDC, level
transmitter based on the concept of pulse burst radar. The
electronics are housed in an ergonomic housing comprised
of two tandem compartments angled at a 20-degree angle
for ease of wiring and calibration. These two compartments
connect via a watertight feed-through.
3.2 Theory of Operation
3.2.1 Pulse Burst Radar
PULSAR Model R86 is a top-mounted, downward-looking
pulse burst radar operating at 26 GHz. Unlike true pulse
devices (GWR, for example) that transmit a single, sharp
(fast rise-time) waveform of wide-band energy, PULSAR
Model R86 emits short bursts of 26 GHz energy and meas-
ures the transit time of the signal reflected off the liquid
surface. Distance is calculated utilizing the equation:
Distance = C (Speed of light)
×
Transit time/2, then devel-
oping the Level value by factoring in application-specific
configuration. The exact reference point for distance and
level calculations is the Sensor Reference Point—bottom of
an NPT thread, top of a BSP thread or face of a flange.
1 ns
500 ns
Distance = c
×
(time
÷
2)
ANSI or DIN
Welded Flange
Sensor Reference Point
Pulse
Pulse Burst
