Model 463 Bridgesensor Features ! Complete Strain Gage Bridge Signal Conditioner ! Isolated 10 Volt Output ! Bridge Balance with 80% Tare Offset Capability ! Excitation Supply Capable of Driving Four Load Cells ! AC Powered ! Rugged Epoxy Encapsulated Design Applications ! Weighing with Load Cells ! Low Frequency Strain Measurements Description ! Process Control Pressure Transducers The Model 463 is a self contained, AC powered signal conditioner for bridge type instrumentation. It contains a precision instrumentation amplifier with isolated, filtered output and a highly regulated, low noise, adjustable output bridge excitation source. The unit is completely encapsulated for use in rugged environments. ! Can Be Used With All Types of Low Output Sensors 463 Block Diagram A 2401 Stanwell Drive * Concord, California 94520 * Ph: 925/687-4411 or 800/542-3355 * Fax: 925/687-3333 * www.calex.com * Email: sales@calex.com 1 4/2001 Model 463 Bridgesensor Specifications Getting Started with the Model 463 NOTE: Unless otherwise noted, specifications apply after 1 hour warm up at 25C ambient. Temperature coefficients apply between 0C and 55C ambient. 1. Excitation Supply. If remote sensing is not used, connect +Sense to +Excitation, terminal 3 to 4, and connect -Sense to -Excitation, terminal 1 to 2. These connections must be made to adjust the supply as in step 2. 2. Apply power to the Model 463 and adjust the Excitation supply. Turn SWB-1 "ON" for a fixed 10 Volts. This will set the supply to 10.2 2.5% and provide the best temperature stability. For voltages between 5 and 10 Volts, place SWB-1 in the "OFF" position and set the Excitation Supply with potentiometer E. SWB-2 may be in either position. 3. Turn the power to the Model 463 "OFF" and connect the load cell to the Model 463 Excitation terminals and the Amplifier Inputs. 4. Turn on power to the 463. 5. Turn SWA-3 "ON". (To set output ZERO) 6. Select the expected full scale signal range according to the table with SWA-4 and SWA-5. If the output from the load cell is not known, set both SW-4 and SW-5 "ON" for the 40-50mV range. 7. Select required ZERO output range. SWA-2 "ON" for zero Volts or SWA-2 "OFF" for +2 Volts. 8. Adjust D potentiometer for 0 or +2 Volts. 0 or +2 Volts 9. Turn SWA-3 "OFF". Expect output to change. 0.3mV/C typical 10. Apply no load or dead weight to load cell. -3 to +10 Volts 5 mA maximum 10 Hz, 2 pole 11. Adjust TARE potentiometers A and B for the same ZERO output set in Step 8. SWA-1 "OFF" provides a bridge output balance of -3mV to +15mV, and "ON" between +15mV and +25mV, referred to the amplifier input. This adjustment does not change the output of the bridge. Isolation Input to Output Amplifier Gain Adjustment Range Input for 10V Output Linearity Temperature Stability Input Noise .1 Hz to 10 Hz Input Offset Temperature Coefficient Tare Adjustment Range Bridge Balance Referred to Input Temperature Coefficient Input Resistance Differential and Common Mode Common Mode Rejection DC to 60Hz Common Mode Input Output Zero Adjust Temperature Coefficient Referred to Output Output Voltage Range Current Frequency Response, -3dB Response Time Rise Time 10% to 90% To 0.1% of Final Value Bridge Supply 700 V D C 60pF 200 to 2000 5 mV to 50 mV 0.005% of Full Scale 50 PPM (0.005%/C) 2V P-P 0.5V/C typical -3mV to +25mV Equals 80% F.S. of 3mV/V cell 1V/C typical 1000 megohm 90 dB minimum 0 to +5 Volts maximum 35 ms 90 ms Voltage Adjustment Range 5 to 10 Volts Temperature Coefficient Fixed Temperature Coefficient Load Current Regulation - Load and Line Output Noise 120 Hz Bandwidth 100 PPM/C typical 10.2V 2.5% 60 PPM/C typical 0 to 120 mA 0.02% maximum Pow er Input Optional Line Isolation Capacitance Dielectric Withstand Environment Ambient Operating Storage Weight Siz e 12. Apply full scale load and adjust SPAN (GAIN) potentiometer C for the desired full scale output. Set Range switches SWA-4 and SWA-5 as required. A 13. Remove full scale load and check ZERO output. Adjust FINE TARE potentiometer A if required. 14. Recheck full scale as in Step 12. 15. End. 1 mV RMS, maximum 115 VAC, 10V 50/60 Hz @ 6 VA 100, 220 or 230 VAC, 10% Note: 60 pF typical 1100 Volts RMS If the amplifier is used without using the 463 Excitation Supply, the external power supply low side must be connected to the -EXCITATION pin 2 on the Model 463, or one of the inputs must be tied to pin 2, -EXCITATION. This provides a DC return path for the finite amplifier input current. -25C to +55C -25C to +85C 18 oz. (510 grams) 3.75" L x 2.0" W x 2.87" H (9.53 cm x 5.1 cm x 7.62 cm) 2401 Stanwell Drive * Concord, California 94520 * Ph: 925/687-4411 or 800/542-3355 * Fax: 925/687-3333 * www.calex.com * Email: sales@calex.com 2 4/2001 Model 463 Bridgesensor Amplifier SWA - Control Switch The amplifier is a true differential input, low drift Instrumentation amplifier with less than 100pA input current. It has a common mode range of 5 Volts with respect to the - EXCITATION supply terminal and a minimum of 90dB rejection of the common mode voltage. The input amplifier and excitation supply are DC isolated from the AC line and the output. Tare Weight Compensation The Model 463 has two different zero controls. One is called the OUTPUT zero and can be set to 0 Volts or + 2 Volts with SWA-2. The other zero control is called TARE. SWA-1 allows the selection of one of two TARE ranges, -3mV to 15mV or +15mV to +25mV. Potentiometers are available for COARSE and FINE TARE adjustments. SWA-4 ON OFF ON OFF Connecting to a Sensor Any amplifier has a finite input current which must have DC return path to the amplifier power supplies. This path is automatically provided when the Model 463 Bridge Excitation Supply is used to excite the sensor. If an external supply is used, one side of the external supply must be connected to the Model 463 -EXCITATION, Terminal 2. Be sure that the common mode voltage limits are observed. This would generally limit the external power supply to 10 Volts assuming that half the voltage would be common mode, as is the case when exciting a full bridge. SWA-1 OFF ON Tare Range -3mV to +15 mV +15 mV to +25 mV SWA-2 OFF ON Zero Voltage +2 V 0V SWA-5 ON ON OFF OFF Span Range 40 mV to 50 mV 20 mV to 40 mV 10 mV to 20 mV 5 mV to 10 mV Mechanical Specifications When the full scale output of a sensor is measured in millivolts, say 10 millivolts, care must be exercised in wiring systems. At 10 millivolts full scale, each microvolt (10-6 Volts) contributes 0.01% of full scale output. Wire connections can generate microvolts of potential due to contact potentials. These will also be thermoelectric potentials and thus vary with temperature differences. All wires used in connecting up the Model 463 should be of the same material. If any intervening connections are made such as a terminal block, the terminal block connecting points should have good thermal contact so they will always be at the same temperature and thus cancel each other. A Transducer Excitation The bridge excitation supply voltage is set by SWB-1 and potentiometer E. Set SWB-1 ON for a fixed 10 Volts. This will provide the best temperature stability. The supply can be adjusted between 5 and 10 Volts by setting SWB-1 OFF and adjusting potentiometer E. The supply will deliver up to 120mA current at any voltage setting to power up to four 350 ohm sensors. Terminal Strip Assignments SWB-1 ON OFF Excitation Voltage Fixed 10 Volts Adjustable Screw Terminal Function Screw Terminal Function 1 2 3 4 5 -SENSE -EXCITATION +SENSE +EXCITATION AC 6 7 8 9 10 AC +SIGNAL -SIGNAL OUTPUT COMMON 2401 Stanwell Drive * Concord, California 94520 * Ph: 925/687-4411 or 800/542-3355 * Fax: 925/687-3333 * www.calex.com * Email: sales@calex.com 3 4/2001