Brooks Instrument BM50 - Manual (Page 32)

3-8
Section 3 Operation Installation and Operation Manual
X-PD-BM-Ovals-eng
Part Number: 541B031AAG
January, 2009
BM Oval Series
Flowrate - 2
The settings for Total and flowrate are entirely separated. In this way, different
measurement units can be used like cubic meters for Total and litres for
flowrate.
FLOWRATE; MEASUREMENT UNIT - SETUP LEVEL 21:
Setup - 21 determines the measurement unit for flowrate.
The following units can be selected:
mL - L - m 3 - mg - g - kg - ton - GAL - bbl - lb. - cf - rnd(rnd for RPM)_ (no
unit).
Alterations of the measurement unit will have consequences for operator and
SETUP-level values. Please note that the K-factor has to be adapted as well
(the calculation is not done automatically).
FLOWRATE; TIME UNIT - SETUP LEVEL 22:
The actual flowrate can be calculated per second (SEC), minute (MIN), hour
(HR) and day (DAY).
FLOWRATE; NUMBER OF DECIMALS DISPLAYED - SETUP LEVEL 23:
This setting determines for Flowrate the number of digits following the
decimal point. The following can be selected:
00000 - 1111.1 - 2222.22 - 3333.333
FLOWRATE; K-FACTOR - SETUP LEVEL 24:
The K-factor is used to calculate a volumetric quantity based on the number
of pulses based on the number of pulses received within a specified time
period. This K factor is determined on the basis of the measurement unit and
the pulses generated per measurement unit by the flow meter. Enter the
number of pulses generated by the flowmeter per selected measurement unit
(e.g. per Litre). The more accurate the K-factor, the more accurate the
functioning of the system will be. For examples see SETUP 13.
FLOWRATE; NUMBER OF DECIMALS K-FACTOR - SETUP LEVEL 25:
This function determines the number of decimals for the K-factor (SETUP
24).
The following can be selected:
0 - 1 - 2 - 3 - 4 - 5 - 6
Please note that this SETUP - influences the accuracy of the K-factor
indirectly. This setting has NO influence on the displayed number of digits for
“flowrate” (SETUP 23).
FLOWRATE; CALCULATION - SETUP LEVEL 26:
The flowrate is calculated by measuring the time between pulses. As several
types of flowmeters have an unequal pulse-train, it is advised to calculate the
flowrate over several pulses, for example 10 pulses; the maximum value is
255 pulses. Please understand that the calculation time for very low
frequencies (0.1-5 Hz) is influenced by this setting as well; so do not program
too many pulses! When the frequency is above 3 kHz during normal
conditions, it is advised to calculate over 50 or more pulses.
FLOWRATE; CUT-OFF TIME - SETUP LEVEL 27:
With this setting, you determine a minimum flow requirement threshhold, if
during this time less than XX-pulses (SETUP 26) are generated, the flowrate
will be displayed as zero. Time in seconds.
Display - 3
DISPLAY; FUNCTION - SETUP LEVEL 31:
The large 17mm digits can be set to display Total or flowrate digits at
operator-level. When Total is selected, both Total and flowrate are
displayed simultaneously. When flowrate is selected, Total will only be
displayed after pressing select.