Series 668B & 668DCompact Differential Pressure Transmitter

T h e ma t e r i a l s i n c l u d e d i n t h i s c o mp i l a t i o n a r e f o r t h e u s e o f D w y e r I n s t r u me n t s , I n c . p o t e n t i a l c u s t o me r s

a n d c u r r e n t e mp l o y e e s a s a r e s o u r c e o n l y . T h e y ma y n o t b e r e p r o d u c e d , p u b l i s h e d , o r t r a n s mi t t e d e l e c t r o n i c a l l y f o r c o mme r c i a l p u r p o s e s . F u r t h e r mo r e , t h e C o mp a n y ’ s n a me , l i k e n e s s , p r o d u c t n a me s , a n d l o g o s , i n c l u d e d w i t h i n t h e s e c o mp i l a t i o n s ma y n o t b e u s e d w i t h o u t s p e c i fi c , w r i t t e n p r i o r p e r mi s s i o n f r o m

D w y e r I n s t r u me n t s , I n c . ©C o p y r i g h t 2 0 1 6 D w y e r I n s t r u me n t s , I n c .

Summary

• New 668B/D unit features• Model dependent front or bottom pressure

connections

• Protection from incorrect wiring & 15 psi overpressure

• Model dependent current or voltage outputs

• Terminal cover included but replacement cover is

available and separately orderable.

668B

668D

Summary

668B/D

Pressure Ranges

Accuracy

Pressure Limit

Outputs

• 668B/D: Down to 0.1” w.c.

• 668B/D: 0.8% FS

• 668B/D: 15 psi Overpressure

• 668B/D: 4-20 mA, 0-5 VDC, 0-10 VDC

Model ChartModel Chart

Example 668 X -XX -X 668B-05-2Series 668 Compact Differential Pressure Transmitter

Connection B Front D Bottom

Unidirectional Pressure Ranges

01 0 to 0.1 in w.c. 21 0 to 2 in w.c. 02 0 to 0.25 in w.c. 22 0 to 0.4 in w.c. 03 0 to 0.5 in w.c. 04 0 to 1 in w.c. 05 0 to 2.5 in w.c. 06 0 to 5 in w.c. 07 0 to 10 in w.c. 08 0 to 25 in w.c. 09 0 to 50 in w.c. 10 0 to 100 in w.c.

Bi-Directional Pressure Ranges

12 0 to ±0.1 in w.c. 13 0 to ±0.25 in w.c. 14 0 to ±0.5 in w.c. 15 0 to ±1 in w.c. 16 0 to ±2.5 in w.c. 17 0 to ±5 in w.c. 18 0 to ±10 in w.c. 19 0 to ±25 in w.c

Output 1 4 to 20 mA 2 0 to 10 VDC 3 0 to 5 VDC

• Extremely Low Pressure Ranges– Uni-Directional Ranges Down to 0.1” w.c.– Bi-Directional Ranges Down to ±0.1” w.c.

• Current & Voltage Output Models Available– 4 to 20 mA– 0-5 VDC– 0-10 VDC

668B/D Features & Benefits

• Compact & Lightweight design makes installation simple & easy– Units are protected against incorrect wiring &

include a protective terminal cover– Pressure ports designed to be used with push-on

tubing with:• 3/8” ID for lengths up to 80’ (25 m)• 1/4” ID for lengths up to 250’ (75 m)• 1/2” ID for lengths up to 720’ (220 m)

668B/D Features & Benefits

• HVAC Markets– Primary use: Accurately measure

differential pressure & send analog signal to a controller or PLC

Applications:• Measuring Pressure Differences

in Clean Rooms & Isolation Rooms

• Measuring Duct Static Pressure• Measuring Pressure in Variable

Air Volume Systems• Filter Monitoring

Series 668B/D Markets

• The 668B/D can be used to measure the pressure difference between two rooms or a room & the hallway

• Can be used to monitor a positive pressure or as an open door/broken seal alarm

Clean Rooms & Isolation RoomsSeries 668B/D Applications

• Other Dwyer products to consider:– Static Pressure Accessories– CO2, Humidity, Temperature Transmitters

(CDTA, CDTR)– Temperature Sensors (TE)– Fume Hood Monitor (670)– Differential Pressure Switches (ADPS,

EDPS)

• The 668B/D can be used to measure the velocity & static pressure in a duct to determine the air velocity

• The 668B/D can also be used to monitor the static pressure in a duct so that it does not exceed design constraints

Series 668B/D ApplicationsDuct Static Pressure

• Other Dwyer products to consider:– Static Pressure Accessories– AQTIA (UHH2, AP2, RP2, VP2, WDPM)– Pitot Tubes

• The 668B/D is used to measure the velocity pressure delivered to each zone to give feedback to the PLC/VFD

• The 668B/D is used to measure the pressure drop across a heating or cooling coil

Series 668B/D ApplicationsVariable Air Volume

• Other Dwyer products to consider:– Static Pressure Accessories– Series TE VAV Temperature Sensor– Relative Humidity Transmitters (RHP)– CO2 Transmitters (CDT)– Combo Units (CDTA, CDTR)

• The 668B/D can be used to measure the pressure drop across air filters

• As the filter accumulates debris, the pressure drop will increase

Series 668B/D ApplicationsFilter Monitoring

• Other Dwyer products to consider:– Static Pressure Accessories– DP Switches (ADPS, EDPS, 1800,

1900)– Control Enclosures (CSE, SSE)– Manometers (MARK II 25)– DP Gauges (Magnehelic)

668B Specifications

SPECIFICATIONS

Services: Air & Non-Conductive Gases

Accuracy: ±0.8% FS

Temperature Limits: Operating: 0 to 170° F (-18° to 77° C)Storage: -40° to 185° F (-40° to 85° C)

Compensated Temperature Range: 40° to 170°F (4.4° to 77°C).

Pressure Limits: 15 psig (1 bar)

Thermal Effect: ±0.03% FS/°F (±0.054% FS/°C)Power Requirement: 12 to 32 VDC

Output: 4-20 mA, 0-5 VDC, or 0-10 VDC

Zero Adjustment: Accessible under the small terminal cover

Loop Resistance: RL ≥ 50*(Vs – 12)

Electrical Connections: Terminal Strip

Process Connections: 3/16 OD barbed brass for 1/8 ID push-on tubing ̋ ̋Process Connection

Location: Front

Weight: 4.0 oz (113 g)

Enclosure: Stainless steel and PC+ABS alloy, UL 94 V-0 rated

Agency Approvals: CE

668B Specifications

SPECIFICATIONS

Services: Air & Non-Conductive Gases

Accuracy: ±0.8% FS

Temperature Limits: Operating: 0 to 170° F (-18° to 77° C)Storage: -40° to 185° F (-40° to 85° C)

Compensated Temperature Range: 40° to 170°F (4.4° to 77°C).

Pressure Limits: 15 psig (1 bar)

Thermal Effect: ±0.03% FS/°F (±0.054% FS/°C)Power Requirement: 12 to 32 VDC

Output: 4-20 mA, 0-5 VDC, or 0-10 VDC

Zero Adjustment: Accessible under the small terminal cover

Loop Resistance: RL ≥ 50*(Vs – 12)

Electrical Connections: Terminal Strip

Process Connections: 3/16 OD barbed brass for 1/8 ID push-on tubing ̋ ̋Process Connection

Location: Bottom

Weight: 4.0 oz (113 g)

Enclosure: Stainless steel and PC+ABS alloy, UL 94 V-0 rated

Agency Approvals: CE