Signal Conditioner, B220-885 K Factor Scaler and B220-900 Programming Software Kit
Page iv November 2013
Turbine Rotor
Magnetic Pickup
User Manual
INTRODUCTION
The Blancett K Factor Scaler is a field adjustable frequency divider, which converts the output signal from a turbine meter
or like device with a magnetic pickup or pulse output to an input compatible with a PLC, RTU, CPU data acquisition card or
similar totalizer device. The adjustable frequency divisor, referred to as a K factor, allows pulses sent from a turbine meter to
accumulate into a unit recognizable by an end device, such as a PLC, for counting and display.
The use of different K factor values allows the device to display in any number of volumetric measurements such as gallons,
cubic meters, liters, barrels, and like units. The calibration sheet usually provided with a turbine meter lists a nominal K factor
tested to a specific volumetric flow rate. The K factor when placed into the K Factor Scaler provides an output pulse for
each unit of volume that passes through the turbine. Any units of volume are possible by recalculating the K factor with the
appropriate conversion factor.
In addition, if the K factor is set to one, the K Factor Scaler becomes a preamplifier converting the frequency from a low output
level turbine meter to the logic level needed by a PLC or CPU data acquisition card.
The programmable K Factor Scaler provides a lower cost alternative to the Blancett model B220-880 K Factor Scaler. The
programmable version uses fewer components, reducing the size of the board and enclosure.
OPERATING PRINCIPLE
Fluid passing through the turbine causes it to rotor to spin at a speed proportional to the fluid velocity. As each rotor blade
passes through the magnetic field, the blade generates an AC voltage pulse in the pickup coil at the base of the magnetic
pickup (see Figure 1). These pulses produce an output frequency proportional to the volumetric flow through the meter. The
output frequency with further processing represents flow rate and/or totalization of fluid passing through the flow meter.
or
Other Frequency
Output Device
Output
Signal
Figure 1: Schematic illustration of electric signal generated by rotor movement
The K Factor Scaler input amplifier modifies the signal generated by the turbine. The amplifier sends the modified signal to an
onboard microcontroller, which counts pulses up to a predetermined number controlled by the K factor value. The range of
the K factor is between 1…999,999,999. The predetermined value once reached triggers a pulse from the output circuitry.
The K factor is user adjustable through the programming interface. The duration of the output pulse is also selectable. At the
end of the output pulse, the internal counters reset to zero and the process starts over.
Page 5 November 2013
Signal Conditioner, B220-885 K Factor Scaler and B220-900 Programming Software Kit
SPECIFICATIONS
External Power
Input Voltage 8.5…30V DC (diode protected).
Maximum Current Draw 18 mA (using internal resistor @ 30V DC input).
Environmental
Operating Temperature –22…158° F (–30…70° C).
Inputs (Magnetic Pickup)
Frequency Range 0…4000 Hz.
Trigger Sensitivity 30 mV p-p…30V p-p.
Output Signal
Max Voltage30V DC.
Max Power 0.25 W.
Pulse Output (using internal pullup resistor)
Maximum Current8 mA.
VH = Power input voltage – 0.7V DC.
VL = Less then 0.4V @ maximum input power.
Internal Pullup Resistor3.6 k (enabled/disabled by jumper).
Pulse Length150 µs, 1 ms, 25 ms, 100 ms, 500 ms, 1 s, or auto mode.
EnclosureKillark aluminum capped elbow Y-3.
Agency Listings
Hazardous Locations.
CSA
Pollution Degree 2
Overvoltage Category III
Class I, Div 1, Groups B, C and D; Class II, Groups E, F, and G; and Class III.
Type 4X; T6 @ 70° C.
C22.2 No. 30 for Canada.
Normally only non-conductive pollution occurs. Occasionally, a temporary conductivity
caused by condensation must be expected.
Distribution level, fixed installation, with smaller transient overvoltage than installation
category IV (Primary supply level).
MPORTANTI
For this CSA rating to be valid, the circuit board must be mounted in a certified Killark one inch model Y-3 conduit outlet box.
Page 6 November 2013
Programming
Internal 3.6k Ω
Resistor Jumper
Available Current =
(Input Voltage - 0.7V)
User Manual
INSTALLATION
Refer to Figure 2 for the I/O terminal connections. The board connections include power input, turbine meter input, and the
pulse output to a totalizing device.
Port
Output
123456
Pullup
Output
Vin
Vin
Signal
Input
Figure 2: Input/Output terminal connections
Enclosure Mounting (necessary for CSA certication)
If supplied without an enclosure you must mount the circuit board assembly within a certified Killark one inch NPT model Y-3
conduit elbow outlet box to maintain the CSA “Ordinary Locations” certification.
Electrical Connections
The board connections include power input, turbine meter input, and the pulse output to a totalizing device.
Power
The K Factor Scaler requires 8.5…30V DC to operate and is diode protected. Figure 2 shows the supply polarity.
Turbine Meter
The turbine meter connections are non-polarized. Blancett recommends shielded, twisted pair wire for this connection.
Pulse Output
Either the internal or an external pullup resistor is required for the K Factor Scaler to provide an output pulse. An onboard
jumper controls the pullup resistor selection. With the jumper installed, the internal pullup resistor is connected. Without the
jumper, an external pullup is required. Refer to Figure 2 for the I/O terminal connections.
Internal Pullup Resistor
The internal pullup resistor allows for a simple installation, but be careful to ensure that the device being connected to
the pulse output can accept voltage levels as high as the supply feeding theK Factor Scaler. Another important setup
consideration when using the internal pullup resistor is to make certain the output pulse from the K Factor Scaler can supply
enough current for the receiving device to read the pulse. Calculation of the available current that the K Factor Scaler can
supply to the receiving device uses the following equation (see Figure 3).
Using the above equation the maximum current available at an input voltage of 30V is 8 mA. Verify that the receiving device
input current requirement is below this value for proper operation. Otherwise, an external pullup resistor less than 3.6 k
is required.
Page 7 November 2013
R =
Supply Voltage
Current
Signal Conditioner, B220-885 K Factor Scaler and B220-900 Programming Software Kit
Internal 3.6k Ω
Pullup
Resistor Jumper
Open Collector
Pulse Output
8 mA
Maximum
Figure 3: Wiring schematic with internal pullup resistor in circuit
Output
Output
Vin
Vin
Vin
12345 6
TB1
3.6k Ω
Internal
External Pullup Resistor
Using an external pullup resistor offers the end user greater flexibility in controlling the output pulse provided by the
K Factor Scaler. Power sources and receiving devices differ in individual situations. This fact requires the use of different pullup
resistor values. Connection of the external pullup resistor is between the receiving device’s input and external power source
(see Figure 4). The power source voltage is the maximum input voltage (of the pulse) to the receiving device. Refer to the
following equation to help determine the pullup resistor value needed.
Where:
R = Resistor value in ohms
Supply Voltage = External supply voltage connected to the external pullup resistor
Current = Input current required by the receiving device in amps
After the resistor value is calculated, make sure in the following equation that power (P) is less than or equal to 0.25 Watts. P
represents the output power capability. This value should not exceed 0.25 Watts. Damage to the K Factor Scaler circuit is likely
by exceeding this value. Raising the resistor value will decrease the available power output and safeguard the circuit.
Open Collector
Pulse Output
250…10k
Pullup
Resistor
100 mA
Maximum
Output
Output
Vin
Vin
123456
TB1
Internal
+V
Vin
Figure 4: Wiring schematic using an external pullup resistor
Page 8 November 2013
To determine the maximum current available using a specific pullup resistor use the following equation.
User Manual
Current Draw =
0.25 Watts
External Pullup Resistor
STARTUP
Using Optional Programming Software Kit B220-900
(Software sold separately)
The programmable K Factor Scaler can be factory or user configured through a serial port of a PC by a Windows compatible
software utility. A programming adapter is required that interfaces the serial port from the PC to the programming port on
the board.
To program the K Factor Scaler:
1. Begin with the power turned o and connect the adapter cable to the K Factor Scaler board using the programming
port (see Figure 2).
2. Connect the serial-to-TTL converter to the adapter cable. See Figure 5.
3. Attach the serial extension cable to the serial-to-TTL converter and connect the opposite end to an available nine-pin
serial port of a PC.
OTE:NFor computers without a 9-pin serial connection a serial to USB converter may be required.
4. Turn on the power to the K Factor Scaler.
OTE:NPower to the K Factor Scaler is required in order to perform any programming.
Model 232LPTTL
RS-232TO TTL Converter
RS-232
OR
- OUTPUT
+ OUTPUT
8.5 - 30 VDC
TURBINE
PICK UP
PROGRAMMING
®
C US
FILE #215035
- VIN
+ VIN
K-FACTOR SCALER
INPUT 8.5 - 30 VDC
MAX INPUT CURRENT: 18 mA
TTL
PORT
INTERNAL
123456
3.6K PULL-UPRESISTOR
JUMPER
1 2 3 4 5 6
Flow Meters
Racine, WI
U.S.A.
B220-886
LOGICRS232
Serial Interface Converter
Figure 5: Interface connection
The programming interface uses two functional divisions as shown in Figure 8. The Program Values column contains the
user-selected information for downloading into the K Factor Scaler. The Board Values column shows the information that the
K Factor Scaler currently contains and is not alterable by the user. The Board Values column will only display the contents of
the board after performing a Program, Read or Verify function.
Selection of the proper computer serial port within the Blancett K Factor programming software is required for it to
communicate with the board. From the menu bar, select Tools and then Com Port. Select the com port (1…16) that the serial
programming cable is connected to on the computer.
Page 9 November 2013
Signal Conditioner, B220-885 K Factor Scaler and B220-900 Programming Software Kit
Blancett K-Factor Programming Software
File Tools Version
FileOptionsTools
Program
Program ValuesBoard Values
Read
K-Factor
Verify
Com Port
Pulse Width
150us
1ms
25ms
100ms
500ms
1s
Auto
Pulse Output
High
Low
Program
Status: Com19/23/2008
Status: IdleCom Port 1
K-Factor
Pulse Width
150us
1ms
25ms
100ms
500ms
1s
Auto
Pulse Output
High
Low
ReadVerify
Com 1
Com 2
Com 3
Com 4
Com 5
Com 6
Com 7
Com 8
Com 9
Com 10
Com 11
Com 12
Com 13
Com 14
Com 15
Com 16
Blancett K-Factor Programming Software
File Tools Version
FileOptionsTools
Program
Program ValuesBoard Values
Read
K-Factor
Verify
Com Port
Pulse Width
150us
1ms
25ms
100ms
500ms
1s
Auto
Pulse Output
High
Low
Program
Status: Com19/23/2008
Status: IdleCom Port 1
K-Factor
Pulse Width
150us
1ms
25ms
100ms
500ms
1s
Auto
Pulse Output
High
Low
ReadVerify
Figure 6: Tools drop downFigure 7: Com port choice drop down
If the serial port selected is invalid, the software will show the message ERROR– Invalid Com Port when trying to program
the board. If the serial port selected is the incorrect port (or if there is a problem with the cable), the software will show the
message << No Response >> after trying to program the board.
OTE:NAll information under in the Program Values column is required before the software allows the downloading
of information.
Pressing Program downloads the K factor, pulse width and pulse output values to the K Factor Scaler. At the completion of
the programming cycle, the circuit performs automatic verification of the downloaded information. If disconnected from the
power the K Factor Scaler retains downloaded values in memory.
Pressing Read loads the current information from the K Factor Scaler and displays it in the Board Values column of the
PC software.
Verify performs the same function as Read, but compares the Board Values to the Program Values and displays an error if the
two do not match.
Conguration
Configuring the K Factor Scaler consists of the following four items:
1. Setting the K factor (divider).
2. Setting the output pulse width.
3. Setting the pulse output level normally high or normally low.
4. Setting the output pulse to use the internal or external pullup resistor.
Page 10 November 2013
Blancett K-Factor Programming Software
File Tools Version
FileOptionsTools
Program ValuesBoard Values
K-Factor
K-Factor
User Manual
Pulse Width
150us
1ms
25ms
100ms
500ms
1s
Auto
Pulse Output
High
Low
Program
Status: Com19/23/2008
Status: IdleCom Port 1
Figure 8: Programming software screen
Pulse Width
150us
1ms
25ms
100ms
500ms
1s
Auto
Pulse Output
High
Low
ReadVerify
Setting the K Factor
The K factor is the ratio of input pulses per each output pulse and can be viewed as a divisor. The minimum K factor can be set
to one where each input pulse yields an output pulse. The maximum K factor can be set to 999,999,999 where it would take
this many input pulses to yield one output pulse.
The K factor is set by entering it in the Program Values column of the software under K Factor. The K factor will be programmed
when Program is pressed, but note that all values must be entered before programming is allowed by the software.
Setting the Output Pulse Width
The output pulse width is the length of time the pulse remains active before resetting to its original state. The K Factor Scaler
has a total of six different pulse widths to choose from. Some end devices require that the pulse be a certain length or longer
in order for proper detection of each incoming pulse. For these devices, it is important to select a pulse width that is long
enough for the end device to recognize. See Figure 8 for software control placement.
The pulse width option is set by selecting the desired pulse width radio button in the Program Values column of the software.
The pulse width option will be programmed into the board when Program is pressed, but note that all values must be
entered before programming is allowed by the software.
In addition to the six preset pulse widths, another option, Auto mode, is available. This mode acts in the same manner, but
does not restrain the output pulse to a specific length. Instead, it varies and is dependent on output frequency. The higher
the output frequency, the shorter the pulse width output. The lower the frequency output, the longer the pulse width output.
This option turns off the Pulse Output selection buttons because they does not apply in this mode.
Page 11 November 2013
Signal Conditioner, B220-885 K Factor Scaler and B220-900 Programming Software Kit
Setting the Output Level Normally High or Normally Low
Most end devices will be unaffected by this setting but the K Factor Scaler has the ability to invert the output pulse level.
This option is set by selecting the desired pulse output radio button in the Program Values column of the software. The pulse
output option will be programmed into the board when Program is pressed, but note that all values must be entered before
programming is allowed by the software.
When the pulse output option High is selected, the output level is normally low and the duration of the selected pulse width
is high. When the pulse output option Low is selected, the output level is normally high and the duration of the selected pulse
width is low.
Setting the Output to Use the Internal or External Pullup Resistor
Either the internal pullup resistor or an external resistor must be used for the K Factor Scaler to provide an output pulse. This
option is controlled by the onboard jumper and not by the software.
With the jumper installed, the internal 3.6 k pullup resistor is connected to the input voltage of the board. With the jumper
removed, the internal pullup resistor is disconnected and an external pullup resistor and supply voltage are required.
K FACTORS EXPLAINED
The K factor (with regards to flow) is the number of pulses that must be accumulated to equal a particular volume of fluid. You
can think of each pulse as representing a small fraction of the totalizing unit.
An example might be a K factor of 1000 (pulses per gallon). This means that if you were counting pulses, when the count total
reached 1000, you would have accumulated 1 gallon of liquid. Using the same reasoning, each individual pulse represents an
accumulation of 1/1000 of a gallon. This relationship is independent of the time it takes to accumulate the counts.
The frequency aspect of K factors is a little more confusing because it also involves the flow rate. The same K factor number,
with a time frame added, can be converted into a flow rate. If you accumulated 1000 counts (one gallon) in one minute, then
your flow rate would be 1 gpm. The output frequency, in Hz, is found simply by dividing the number of counts (1000) by the
number of seconds (60) to get the output frequency.
1000 ÷ 60 = 16.6666 Hz. If you were looking at the pulse output on a frequency counter, an output frequency of 16.666
Hz would be equal to one gpm. If the frequency counter registered 33.333 Hz (2 × 16.666 Hz), then the flow rate would be
two gpm.
Finally, if the flow rate is two gpm, then the accumulation of 1000 counts would take place in 30 seconds because the flow
rate, and hence the speed that the 1000 counts is accumulated, is twice as great.
Calculating K factors
Many styles of flow meters are capable of measuring flow in a wide range of pipe sizes. Because the pipe size and volumetric
units the meter will be used on vary, it may not possible to provide a discrete K factor. In the event that a discrete K factor is
not supplied then the velocity range of the meter is usually provided along with a maximum frequency output.
The most basic K factor calculation requires that an accurate flow rate and the output frequency associated with that flow rate
be known.
Example 1
Known values are:
Frequency = 700 Hz
Flow Rate = 48 gpm
700 Hz × 60 sec = 42,000 pulses per min
K factor
Page 12 November 2013
42,000 pulses per min
48 gpm
875 pulses per gallon==
Example 2
Known values are:
Full Scale Flow Rate = 85 gpm
Full Scale Output Frequency = 650 Hz
650 Hz × 60 sec = 39,000 pulses per min
User Manual
K factor
39,000 pulses per min
458.82 pulses per gallon==
85 gpm
The calculation is a little more complex if velocity is used because you first must convert the velocity into a volumetric flow
rate to be able to compute a K factor.
To convert a velocity into a volumetric flow, the velocity measurement and an accurate measurement of the inside diameter
of the pipe must be known. Also needed is the fact that one US gallon of liquid is equal to 231 cubic inches.
Example 3
Known values are:
Velocity = 4.3 ft/sec
Inside Diameter of Pipe = 3.068 in.
Find the area of the pipe cross section.
2
πr
Area =
2
3.068
Area
= π= π x
2
2.35 = 7.39 in
2
Find the volume in one foot of travel.
2
7.39 in2 x 12 in. (1 ft)ft=
88.71in
What portion of a gallon does one foot of travel represent?
231 in
3
= 0.384 gallons
3
88.71 in
So for every foot of fluid travel 0.384 gallons will pass.