Technical Guide
August 2007
TURBINE METER INSTRUMENTATION
The turbine pickoff coil has a high impedance and offers only a low voltage output. Transmission of flow signals requires low impedance and high voltage, and so amplification of the pickoff signal is required.
Daniel Series 1200 and 1500 Liquid Turbine Flow Meters are supplied with the UMB and a dual channel preamplifier as standard. The preamplifier shapes and conditions the pickoff output signal, rendering it suitable for transmission over distances of up to 3,000 feet, with the appropriate cabling.
The UMB allows for either one or two pickoffs. The outputs from the two pickoffs are 90o electrically out of phase, thus facilitating proper dual pulse fidelity checking.
Pickoff Specifications
Type:
Resistance:
Inductance: 250 mH max.
Output: Sinusoidal 40mV
Optional: 2, 3* or 4* pickoff coils *with dual UMB
Preamplifier Performance -
Dual Channel Preamplifier
Inputs:
Supply voltage: 10 - 30 Vdc
Minimum input signal amplitude: 40mV
Powered Pulse Output
Output: 0 to 5V square wave
Frequency range: 0 to 5 kHz Loading: 1 kOhm internal
Variable Voltage Output
Output: 0 to supply voltage square wave
Frequency range: 0 to 5 kHz Loading: 1 kOhm internal
Open Collector Output
Output: Square wave
Frequency range: 0 to 5 kHz
Maximum voltage: 30 Vdc
Maximum current: 125 mA
Maximum power: 0.5 Watts
Transmission Distance 
Without preamp: 20ft (6.1m)
Belden 88442 or equivalent
With preamp: 3,000ft (914m)
Belden 8770 or equivalent
Hazardous Area Classifications
UL / CUL Class 1, Division 1, groups C&D
Nema 4 UL, CUL
CE certified EEx d IIB T6 (ATEX)
DUAL CHANNEL PREAMP
Figure 15 - DualTERMINALChannelIDENTIFICATIONPreamp Terminal Identification Customer Connections
CUSTOMER CONNECTIONS
PICKOFF
WHITE
BLACK OR
RED
CHANNEL A
TB1
1
2 TB2
1 | 2 | 3 | 4 | 5 |
CHA. B OUTPUT COMMON CHA. A OUTPUT COMMON +10 TO 30 VDC | ||||
2
1 TB3
BLACK OR
RED
WHITE
CHANNEL B
PICKOFF
J3 J4
| J1 |
| J2 |
|
|
PREAMP JUMPER CONFIGURATIONS
|
|
|
|
|
| JUMPER POSITIONS |
|
JUMPER | A | B | OUT |
N/A | 40mV. PP MIN | N/A | |
N/A | 40mV. PP MIN | N/A | |
5V.PULSE | SUP. VOLT. PULSE | O.C. | |
5V.PULSE | SUP. VOLT. PULSE | O.C. |
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