Magnetrol Pulsar R96 Functional Safety Manual

3
58-650 Pulsar
®
Model R96 SIL Functional Safety Manual
1.0 Introduction
1.1 Product Description
The Pulsar
®
Model R96 Pulse Burst Radar Level
Transmitter is a loop-powered, 24 VDC level transmitter,
based on Pulse Burst Radar technology. For Safety
Instrumented Systems usage it is assumed that the 4–20 mA
output is used as the primary safety variable. The analog
output meets NAMUR NE 43 (3.8 mA to 20.5 mA
usable). The transmitter contains self-diagnostics and is pro-
grammed to send its output to a user-selected failure state,
either low or high upon internal detection of a failure. The
device can be equipped with or without an LCD display.
Table 1 lists the versions of the PULSAR Model R96 that
have been considered for the hardware assessment.
1.2 Theory of Operation
PULSAR Model R96 is a top-mounted, downward-looking
pulse burst radar operating at 6 GHz. Unlike true pulse
devices that transmit a single, sharp (fast rise-time) waveform
of wide-band energy, PULSAR Model R96 emits short bursts
of 6 GHz energy and measures the transit time of the signal
reflected off the liquid surface. Distance is calculated utiliz-
ing the equation: Distance = C × Transit time/2, then devel-
oping the Level value by factoring in application-specific
configuration.
The PULSAR Model R96 is classified as a Type B device
according to IEC 61508.
1.3 Determining Safety Integrity Level (SIL)
Tables 2 & 3 define the criteria for the achievable SIL
against the target mode of operation in Demand Mode
Operation.
Table 2 shows the relationship between the Safety Integrity
Level (SIL) and the Probability of Failure on Demand
Average (PFDavg).
Table 3 can be used to determine the achievable SIL as a
function of the Hardware Fault Tolerance (HFT) and the
Safe Failure Fraction (SFF) for the complete safety system
(type B – complex components as per IEC 61508 Part 2) of
which the level transmitter is one component.
Model R96, R96-511*-*** (HART)
Table 3
Minimum hardware fault tolerance
Type B sensors, final elements and non-PE logic solvers
SFF
Hardware Fault
Tolerance (HFT)
0 1 2
None: <60%
Not
Allowed
SIL 1 SIL 2
Low: 60% to <90% SIL 1 SIL 2 SIL 3
Medium: 90% to <99% SIL 2 SIL 3
High: ≥99% SIL 3
Table 2
SIL vs. PFDavg
Table 1
Pulsar
®
Model Number
Safety
Integrity Level
(SIL)
Target Average
probability of failure
on demand (PFDavg)
4 ≥10
-5
to <10
-4
3 ≥10
-4
to <10
-3
2 ≥10
-3
to <10
-2
1 ≥10
-2
to <10
-1

Magnetrol Pulsar R96 Specifications

General

Brand	Magnetrol
Model	Pulsar R96
Category	Transmitter
Language	English