Badger Meter PFT420 Specifications

FT-420B

PFT-420

RST-420

Analog Flow Transmitter (4-20 mA)

Models PFT-420, PFT-420/2, FT-420B & RST-420

DESCRIPTION

The models PFT-420, PFT-420/2, FT-420B and RST-420 are versatile analog flow transmitters for use with the complete line of Badger Meter flow meters. The PFT housings are plastic. The FT housing is cast bronze. These solid-state units produce a 4…20 mA DC output signal through a two-wire design. They also provide a digital pulse output. The outputs are isolated from power supply negative.

The 4…20 mA output signal is directly proportional to the rate of flow through the meter. The signal has excellent linearity, accuracy and repeatability.

OPERATION

The input pulses generated by the reed switch sensor located within the transmitter assembly are converted to a standard 4…20 mA control signal. This signal is proportional to the flow of fluid passing through the flow meter. The input pulses are also converted to a square wave signal that is available as an open collector transistor. This digital pulse output is compatible with most totalizers and batch controllers. Power for the device can be obtained from a 10…36V DC control loop.

APPLICATIONS

These flow transmitters will precisely condition and transmit flow meter signals for process control in the chemical, food and beverage, water conditioning, pharmaceutical and any other industry where measurement and control of fluid flow is required. The transmitter outputs are compatible with most process controllers, totalizers and flow indication devices, such as chart recorders and other data logging devices.

FEATURES

• Solid-state circuitry, long life, high reliability

• NEMA 4X rating (PFT style housing)

Example

You have a 2" turbo meter and the pulse counter registers 2000 pulses/minute at full flow. A 2" turbo meter has a K-factor of 17.360 pulses per US gallon. 2000/17.360 = 115.2 gpm. Adjust the span for a reading of 20 mA.

K-FACTOR CHART FOR PFT-420, FT-420B

Size Model Max. US GPM Pulses/US Gallon

1/2" OP 6 222.960

1" OP 30 76.640

2" OP 100 20.600 5/8" 25 RCDL 25 198.340 3/4" 35 RCDL 35 126.671

1" 40 RCDL 40 89.781

1" 70 RCDL 70 46.751

CALIBRATION

The factory calibrates this transmitter to the customer specifications provided at the time of order placement. Recalibration generally is not necessary. However, if a particular flow rate is required, use the following recalibration example:

This product is not intended for use in hazardous locations.

First, move the cover. Connect a milliammeter in series with the red lead. Connect a rate indicator or suitable counter to the pulse output. Establish the maximum rate of flow in the system, and determine the number of pulses received per minute. Refer to the meter factor chart found in the flowmeter’s Installation and Operation Manual. Divide the pulses per minute by pulses per US gallon for your particular meter. Using a small screwdriver, adjust the span so the milliammeter registers 20 mA.

XMT-DS-00741-EN-06 (March 2014)

K-FACTOR CHART FOR PFT-420/2

Size Model Max. US GPM Pulses/US Gallon

2" I nd. Turbo 160 17.360

3" I nd. Turbo 350 12.400

4" I nd. Turbo 1000 2.560

6" I nd. Turbo 2000 1.080

K-FACTOR CHART FOR RST-420

Size Model Max. US GPM Pulses/US Gallon

1-1/2" 120 RCDL 120 23.867

2" 170 RCDL 170 14.565

Product Data Sheet

Reed Switch

Zero

Span

NOTE: Wire colors indicated are for Part # 85552 only.

SPECIFICATIONS

Electrical

Supply Voltage 10…36V DC

Pulse Input

Circuit Interface Schmidtt Trigger

Switch Closure 40…60% duty cycle @ 100 Hz

Digital Output

Opto-isolator Open collector transistor

Max. Voltage 80V DC

Max. Power 200 mW

Pulse Width 1 ms (± 0.1 ms)

Pulse Rate Input rate

Analog Output Two-wire signal/power

Max. Voltage 10…36V DC supply

Current 4…20 mA

Max. Load Resistance (Ohms) = 50 + [50 x (VDC–10)]

Environmental

Operating Temperature – 40…185° F (– 40…85° C)

Humidity 5…100% non-condensing

Enclosures

Performance

Analog Output

Over Voltage Protection Resettable fuse 100 mA

Accuracy Within 0.5% of point (10:1 range)

Repeatability Within 0.2% of point

Max. Ripple 0.1 mA @ 10% of span calibration

Response 3 sec. to within 95% of total change

Operational Drift Less than 10 µamps

Thermal Drift Less than 1 µamp per °C

Span Adjustment 7…24 mA

Zero Adjustment 3…9 mA

Zero Stability 3.97…4.03 mA

Bronze: NEMA 4X Plastic: NEMA 4X

2-wire (signal/power) circuit interface with reversed-polarity protection

TRANSMITTER SELECTION GUIDE

METER

C11

ADD J4 FOR MORE DAMPING

R10

RANGE ADJ

RV1

4-20mA

LOOP

50W + (50 x (supply volts - 10))

Meter Type Bronze Standard (Plastic)

Industrial Turbo — PFT-420/2

RCDL 25, 35, 40, 70 FT-420B PFT-420

RCDL 120, 170 — RST-420

orange

red

(-)

Analog Device

DC Supply

10 to 36 VDC

@ 30mA

Maximum loop resistance:

(+)

ZERO

OFFSET

INPUT

C10

R11

R13

R12

PULSE

OUTPUT

white

black

(-)

(+)

Pulse Output NPN Open Collector

80 VDC Max @ 2.5 mA

R14

64199-

PCB

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Trademarks appearing in this document are the property of their respective entities. Due to continuous research, product improvements and enhancements, Badger Meter reserves the right to change product or system specications without notice, except to the extent an outstanding contractual obligation exists. © 2014 Badger Meter, Inc. All rights reserved.

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