Bronkhorst Multibus - Manual (Page 11)

BRONKHORST ®
Page 11 Operational instructions for digital multibus instruments 9.17.023
2.4.5 Using mathematical functions at a digital instrument
Digital instruments are capable of storing 8 different fluid calibrations. Parameters for these calibrations are stored
inside the instrument and can be read or changed through the field bus or the RS232 connection by means of a PC-
program or a digital Readout and Control module. Factory calibration parameters are secured and can not be changed
unless you have special rights to do this. Selection of another fluid is part of operation and therefore not secured.
Digital instruments will need at least 1 fluid set of calibration parameters for operation.
2.5 M
ULTI
F
LUID
/ M
ULTI
R
ANGE INSTRUMENTS
2.5.1 General information
Multi Fluid / Multi Range (MFMR) instruments are calibrated for standard ranges which can easily be configured for
other fluids and ranges. This applies for both Bronkhorst and its customers. Changing fluid and range can be
performed by means of a simple computer program through the RS232 connection of an instrument. The program can
convert the primal calibration curve inside the instrument to the selected fluid and range.
MFMR instruments can be identified by the text “MFMR” on the instruments identification.
2.5.2 Differences between traditional and MFMR instruments
In traditional digital instruments the parameters capacity, density, unit type, capacity unit etc. are static parameters.
These parameters are used by, for example, read out units or PC-software to convert the measured value in
percentage of the maximum output to a real value in a certain unit.
However in MFMR instruments these parameters are dynamic.
Examples:
An instrument is configured for 2000 ml
n
/min Air.
Changing the capacity unit from ‘ml
n
/min’ to ‘l
n
/min’ effects that the capacity automatically changes from
‘2000’ to ‘2’. The 100% output is not affected.
Changing the capacity from ‘2000’ to ‘1000’ effects that the instruments full scale capacity (100% output)
changes to 1000 ml
n
/min. The instrument is reranged.