ECM BB100, Instruction Manual, Page: 19 / 37

Specifications and Limits
Measurements and Accuracy
Parameter Range Accuracy Repeatability
Liters/min flowrate 4 to 150 1% of reading 0.5% of reading
Ft
3
/min flowrate 0.15 to 5.4 1% of reading 0.5% of reading
Liters total flow 0 to 1000 1% of reading 0.5% of reading
Ft
3
total flow 0 to 100.0 1% of reading 0.5% of reading
Accuracies given for clean meter.
Pressure drop 0.5” H
2
0 at 25 liters/min.
Operational Limits
Blow-by Temperature Range: 0 to 250
°
C, 32 to 482
°
F.
Electronics Temperature Range: -20 to 85
°
C, -4 to 185
°
F.
Output Specifications
Analog Output:
•
0 to 5 V for LPM and CFM volume flowrate
•
0.5 to 4.5 V for Total Liters and Total Ft
3
volume
•
Output Impedance: 100 Ohm
•
Output Connector: Female BNC, Signal = Center, Ground = Shell
Note: The analog output ground is internally connected to the power ground.
Display and Analog Output Update Rate Averaging Filters:
Update Rate Selected
Weighting of Current Data Time Between Updates
“S” Slow 2% 0.80 sec.
“A” Average 5% 0.40 sec.
“F” Fast 12.5% 0.20 sec.
For example, on “F” (Fast), every Flow Averaging Period (programmable from 0.1s, to 8.0s),
the flowrate during that period is determined. This flowrate (Q_new) and a previously
calculated average flowrate (Qavg_old) are used to calculate a new average flowrate
(Qavg_new) according to the weighting formula: Qavg_new = 0.125 x Q_new + (1 - 0.125)
x Qavg_old. Qavg_new is applied to the outputs (display, analog output, and RS-232 output)
every 0.20 second.
Specifications and Limits 15