Dwyer Instruments 648B Series Installation And Operating Instructions

The Series 648B Differential Pressure Transmitter is designed to be used with
clean, dry air and other non-corrosive gases. Each unit features a push-activated
zero function and an associated LED light indicator. With the convenient push-
button, zero calibration can be performed without any additional equipment,
which significantly reduces time and cost for users. The dual color LED indicates
if the transmitter is at normal operation, overpressure, or in the process of zero
Calibration. The enclosure consists of a flame retardant plastic top cover and a
stainless steel bottom plate for ruggedness. The pressure ranges vary from 0.1
in w.c. to 25 in w.c. unidirectional and 0.25 in w.c. to 5 in w.c. bidirectional. Wiring
time is reduced with the removeable terminal block. Each unit features a 2-wire
4 to 20 mA output that is fully protected against short circuiting and incorrect
wiring.

Mounting

Series 648B is designed for mounting by using the two (2) slots (suitable for #6
screws) that are provided on the mounting plate. For optimum performance, isolate
the instrument from vibration and provide relatively clean, dry air to the pressure
ports.
In most applications, preferred installation is with the baseplate mounted vertically
and located on a flat surface in a junction box or attached to a nearby beam. Quick
and easy field replacement is possible by removing the single case screw that
holds the housing to the baseplate and lifting the housing free. The baseplate will
remain mounted and can be used with the replacement units housing.
NOTICE The axis most sensitive to vibration is the one perpendicular to
the baseplate. Avoid mounting with maximum vibration along
axis.

Piping

Two (2) 3/16˝ OD barbed pressure fittings are provided for pressure connection
with 1/8˝ ID push on tubing.
The overpressure limit with the new tension diaphragm construction is up to 15 psi
regardless of range.
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A.
Series 648B Differential Pressure Transmitter
Specifications - Installation and Operating Instructions
TERMINAL
BLOCK
Phone: 219/879-8000
Fax: 219/872-9057
LED
Ø3/16
[Ø4.80]
1-57/64
[48.00]
3-15/32
BRASS
[88.00]
HOLE
BARBS
1-9/16
[39.50]
[25.40]

SPECIFICATIONS

Service: Air and non-combustible, compatible gases.
Wetted Materials: 302 SS, glass, nickel, silicon rubber, polyethylene, acrylic,
ABS and brass.
Accuracy: ±0.8% FS* at room temperature.
*RSS (Root Sum Square) includes non-linearity, hysteresis and non-
repeatability.
Stability: ±1% FS/yr.
Temperature Limits:
Operating: 0 to 170°F (-18 to 77°C);
Storage: -65 to 185°F (-54 to 85°C).
Pressure Limits:
15 psi (100 kPa) proof pressure;
30 psi (200 kPa) burst pressure.
Thermal Effects: ±0.025% FS/°F (0.045%/°C).
Power Requirements: 13 to 32 VDC.
Output Signal: 4 to 20 mA.
Zero and Span Adjustments: Push-button for zero, potentiometer for span.
Response Time: Approximately 10 ms.
Max. Loop Resistance: DC: 0 to 950
Electrical Connection: Detachable euro-style terminal block.
Process Connections: 3/16˝ OD barbed fitting for 1/8˝ ID push-on tubing.
Housing: SS and PC+ABS alloy.
Weight: 3.8 oz (108 g).
Model Range in w.c.
648B-1 0 to 0.1
648B-2 0 to 0.25
648B-3 0 to 0.5
648B-4 0 to 1
648B-5 0 to 2.5
648B-6 0 to 5
648B-7 0 to 10
648B-8 0 to 25
648B-13 0 to ±0.25
648B-14 0 to ±0.5
648B-15 0 to ±1
648B-16 0 to ±2.5
648B-17 0 to ±5
www.dwyer-inst.com
e-mail: info@dwyer-inst.com
Bulletin P-648B
3/16
[4.80]
3-5/32
[80.00]
1
.