background image

Model 3770        

DC STRAIN GAGE PANEL METER 

3770

     1.A.0.3770 

1      

G

E N E R A L  

D

E S C R I P T I O N   A N D  

S

P E C I F I C A T I O N S

The Model 3770 is a single

-

channel panel instrument for traditional wheat-stone bridge type 

sensors; intended for applications involving conventional full arm bridges from 120 to 10K Ohm 
transducers with mV/V ratings between 0.5 and 10.0 mV/V full scale. The  3770 will  supply 
excitation, conditioning  and provide a calibrated Engineering Unit's display and analog output 
signals for the measurement of force, load, torque, pressure and other parameters associated with 
DC based full bridge  sensors. The 3770  is front panel configurable with  user selectable wide 
gain, zero, symmetry, and selectable analog output of voltage and current signals. Display is user 
configured  and  can be independently  adjustable  for  engineering  unit scaling up to ±  199950 
independent of the analog full scale signal. 

The Model 3770 can be either calibrated by the “two-point (dead-weight)” process involving 
known input parameters or through the “Shunt” method using front panel push buttons or rear 
connections for simulated calibration using a known resistance provided internally by the 3770 
or through a user installed resistor value. 

FRONT PANEL VIEW OF 3770 CONTROLS

 

(Front Display Cover Removed)

 

1    2    3    4    5    6    7

C

F

C

C

F

F

1 .         X .            X .           X .           X            0

FINE ADJUST

ZERO

SPAN

1. X. X. X. X 0

ZERO

SPAN

WIDE ADJUST

5000

10000
20000

SYM

DISPLAY SPAN

TARE

+ CAL - CAL

1 2 3 4 5 6 7
ANALOG CTRL

FINE ADJUST

         COARSE ZERO
         FINE ZERO
         COARSE SPAN
         FINE SPAN

WIDE ADJUST

       ZERO
       SPAN

DISPLAY CONFIGURATION

Sw 1,2,3,4     DECIMAL POINT PLACEMENT
Sw 5

      DUMMY ZERO

Sw 6 & 7       DISPLAY RESOLUTION

+ CAL

Shunt Positive

- CAL

Shunt Negative

TARE 

ANALOG CONTROL SETTINGS

1 – VOLTAGE OUTPUT – 5.0 or 10.0 VDC
2 -  CURRENT OUTPUT – 4-20 mA
3 -  ANALOG FILTER – 20 / 200 Hz
4 -  ANALOG FILTER – 20 / 2 Hz
5 -  SHUNT – INTERNAL or EXTERNAL
6 -  EXCITATION VOLTAGE - 10 or 5 VDC
7 -  Not Used

DISPLAY SPAN

       COARSE
       FINE

SYMMETRY

OFF

Page 1

 

Summary of Contents for 3770

Page 1: ...MODEL 3770 DC STRAIN GAGE CONDITIONER SB 1 1 INSTRUCTION MANUAL 3700 Instrument Series...

Page 2: ...of the analog full scale signal The Model 3770 can be either calibrated by the two point dead weight process involving known input parameters or through the Shunt method using front panel push buttons...

Page 3: ...30 ppm C vs Time 10 ppm month Linearity better than 0 03 of full scale Filter 3 pole modified Butterworth 3 dB down at 2 Hz 20 Hz or 200 Hz selectable Fast output always enabled 5 KHz response J3 Pin...

Page 4: ...el Function J1 1 N C No connection J1 2 N C No connection J1 3 HOLD Input Analog Hold command J1 4 TARE Input Analog TARE command J1 5 TARE ENABLE External TARE enable input J1 6 LOGIC COM Logic Commo...

Page 5: ...nd a shorting wire in place of the external shunt resistor position This provides the electrical path for the Calibration Sense line to enable the sensor s internal shunt resistor when the or Shunt Ca...

Page 6: ...rnal or external across the connected four arm bridge sensor for simulated calibration verification check of the sensor s electrical characteristics LOGIC COM R CAL N O Switch J2 HOLD TARE Connections...

Page 7: ...KHz Analog Voltage Output 5 Vdc or 10 Vdc with front panel selectable cutoff filter 2 20 200 Hz Analog Current Output 4 20mA 4 12 20mA at selected cutoff filter SIGNAL SIGNAL SIGNAL SIGNAL SIGNAL SIGN...

Page 8: ...selects Display Full Scale Range Range will equate to an analog output value of 5 Vdc or 10 Vdc per Analog Control switch placement Selection is set for 1 count in 5000 2 counts in 10000 and 5 counts...

Page 9: ...range gain for 0 5 to 10 mV V sensors Display Span Adjustments Used to adjust the digital readout of the 3770 meter the user calibrates the analog output for a specific span value and then adjusts th...

Page 10: ...ion voltage The full scale analog output will be 5 000 Vdc The current output will be set for 4 ma zero and 20 ma will positive full scale The analog low pass filter will be set for 20 Hz Shunt calibr...

Page 11: ...nse leads of the bridge CAL Negative Calibration Activates the SHUNT Negative by switching in the external or internal shunt calibration resistor across the Cal Sense and Sense leads of the bridge TAR...

Page 12: ...t Note that changes in Span Gain will affect Zero Span and Zero re adjustments may need to be repeated to obtain the desired reading Note that the 3770 meter also has independent display adjustment ca...

Page 13: ...potentiometers fully CW Coarse is 22 turns Fine is 25 turns then reverse direction CCW Coarse 11 turns and Fine 13 turns to obtain mid authority of the controls Typically this is done on initial cali...

Page 14: ...scale analog output signal will be 5 VDC or 10 VDC as selected by the Analog Controls of the unit To accomplish the display adjustment change the user would first set the desired display range and dec...

Page 15: ...a factor of 2 Wide Span Position SPAN Low mV V SPAN High mV V 0 3 90 5 80 1 3 30 4 90 2 2 90 4 20 3 2 50 3 60 4 2 10 3 10 5 1 80 2 70 6 1 50 2 30 7 1 30 1 90 8 1 10 1 70 9 1 00 1 40 A 0 84 1 20 B 0 72...

Page 16: ...hase price to the Buyer ANY PRODUCT FOUND TO BE DAMAGED THROUGH CUSTOMER NEGLIGENCE OR MISUSE MAY BE EXCLUDED FROM ANY AND ALL POLICIES CONTAINED IN THIS DOCUMENT ALL EQUIPMENT TO BE REPAIRED OR REPLA...

Reviews: