Emerson Rosemount 8750W, Reference Manual

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Specifications and Reference Data
March 2016
Reference Manual
00809-0300-4750, Rev CA
182
Specifications and Reference Data
Net total reset
Resets the net totalizer value to zero.
Positive zero return (PZR)
Forces outputs of the transmitter to zero flow.
Security lockout
Security lockout switch on the electronics board can be set
to deactivate all LOI and HART-based communicator
functions to protect configuration variables from unwanted
or accidental change.
LOI lockout
The display can be manually locked to prevent
unintentional configuration changes. The display lock can
be activated through a HART communication device, or by
holding the UP arrow for 3 seconds and then following the
on-screen instructions. When the display lock is activated, a
lock symbol will appear in the lower right hand corner of the
display. To deactivate the display lock, hold the UP arrow for
3 seconds and follow the on-screen instructions.
Display auto lock can be configured from the LOI with the
following settings: OFF, 1 Minute, or 10 Minutes
A.1.4 Sensor compensation
Rosemount Sensors are calibrated in a flow lab at the
factory and are assigned a calibration number. The
calibration number must be entered into the transmitter,
enabling interchangeability of sensors without calculations
or a compromise in standard accuracy.
Rosemount 8750W transmitters and other manufacturers’
sensors can be calibrated at known process conditions or at
the Rosemount NIST-Traceable Flow Facility. Transmitters
calibrated on site require a two-step procedure to match a
known flow rate. This procedure can be found in the
operations manual.
A.1.5 Performance specifications
System specifications are given using the frequency output
and with the unit at reference conditions.
Accuracy
Includes the combined effects of linearity, hysteresis, and
repeatability.
Standard system accuracy is ±0.5% of rate from 1 to 39 ft/s
(0.3 to 12 m/s). Accuracy is ±0.005 ft/s (0.0015 m/s) from
the low flow cutoff to 1 ft/s (0.3 m/s).
Optional high accuracy is ±0.25% of rate from 3 to 39 ft/s (1
to 12 m/s).
Other manufacturers’ sensors
When calibrated in the Rosemount Flow Facility, system
accuracies as good as 0.5% of rate can be attained.
There is no accuracy specification for other
manufacturers’ sensors calibrated in the process line.
A.1.6 Analog output effects
Analog output has the same accuracy as frequency output
plus an additional ±4
μ
A at room temperature.
Repeatability
±0.1% of reading
Response time (Analog Output)
20 ms max response time to step change in input
Stability
±0.25% of rate over six months
Ambient temperature effect
±0.25% change over operating temperature range
0
0.5
1.0
1.5
2.0
2.5
0 3
(1) 6
(2) 12
(4) 18
(6) 24
(8) 30
(10)
Velocity in ft/s (m/s)
% of rate
0.5%
0.25%