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Model 6845, Turnkey Strain/Bridge Data Acquisition System


Features

  • 16 or 32 Channels Strain/Bridge Input
  • 10kS/s, 16-Bit Digitizer
  • Bridge Completion, Remote Sense, Shunt Calibration, Low-pass Filters
  • RJ45 Input Connector
  • IRIG Time A, B or G
  • Digital I/O
  • PI660 Turnkey Software Included

Description

Series 6800 is a ready-to-run, high performance laboratory based Measurement System. Enclosures are 3U rack mountable or can be used right on the desktop. 6800 units come equipped with a conditioner, amplifier, filter and digitizer. Each channel has a front mounted RJ-45 connectors for 8-wire bridge transducers. Individual channels have a differential +/- 10V input and can digitize and record data to 16-bit resolution with upper and lower programmable alarm capability that is checked each time the output is digitized. Solutions are available for providing digital outputs based on these alarm conditions.

Systems interface to a familiar Windows based operator workstation over USB 2.0 where the included software, PI660, is used for setup, display & acquisition of the measurement data. PI660 allows for acquisition and control of one or many 6800 systems and provides real time data display. Data can be displayed and recorded in any number of ways, creating a versatile system that can fit any application. Series 6800 is fully compatible with Pacific Instruments’ Series 6000 Transducer Data Acquisition Systems. Custom configurations are easily accommodated with this system; please contact our sales engineers for additional information.




Overview  · Input  · Excitation/Transducer Power  · Amplifier  · Filter  · Digitizer  · Calibration  · Operation  · Data Format  · Data Interface  · Connections  · Mechanical  · Control & Data Processor (CDP) and Operators Workstation (PCCOWU) (Optional)  · Ordering Information 

Overview

Measurement Type
Bridge
Position
Strain Gage

Analog Bandwidth
1 kHz

Sample Rate (Digitizer)
10 kS/s

Excitation/Transducer Power
+/-12V
+/-15V
Voltage

Filter
4-Pole
6-Pole
8-Pole

Analog Output
None


Input

Configuration
8 channels, 2 to 8 wire with guard shield. Bridge config is programmable for 1/4, 1/2 and full bridge. 350 Ohm completion resistor standard, alternate value may be specified.

Balance
Automatic by program control. Balance accuracy ±0.05% of range, ±1 mV RTO. Stability ±0.02% for 8 hours, ±0.005 %/ºC. Range up to 10 mV/V, 2.5 mV/V (350 Ohm bridge) is provided.

Impedance
50 Megohms, shunted by 500 pF.

Protection
±50 Volts differential, ±50 Volts common mode.


Excitation/Transducer Power

Voltage Excitation
Programmable per channel from 0-12 Volts in 1 Volt ±0.1% steps, or adjustable with 3.3 mV resolution.

Current
50 mA limited to 70 mA.

Regulation
±0.01% for ±10% line and no-load to full-load using remote sensing.

Stability
±0.01%, ±0.005 %/ºC

Voltage Excitation Noise
200 µV peak-to-peak

Monitor
Calibration mode measures excitation voltage with ±0.05% accuracy.

Transducer Power
±12 or ±15 Volts (24 V optional) jumper selectable per channel. Transducer power available on separate pins from voltage excitation. Current is 50 mA per channel, limited to 200 mA maximum per card.


Amplifier

Gain
Programmable from 1 to 5,000 in 1, 2, 3, 5 steps with ±0.05% accuracy.

Gain Stability
±0.01%, ±0.004%/ºC.

Linearity (Amplifier)
±0.01% for gains < 1,000, ±0.02% for gains 1,000 and higher.

Common Mode
80 dB plus gain in dB up to 110 dB, DC to 60 Hz for ±10 Volts.

Zero (Amplifier)
Automatic to ±1 µV RTI, ±0.5 mV RTO.

Zero Stability
±5 µV RTI, ±1 mV RTO, ±1 µV/ºC RTI, ±0.2 mV/ºC RTO. Short term: ±2 µV RTI, ±0.4 mV RTO for 8 hours.

Source Current
±10 nA, ±1 nA/ºC.

Noise (10 Hz)
0.1 µV rms RTI, 0.5 mV rms RTO.

Noise (1 kHz)
1.0 µV rms RTI, 0.5 mV rms RTO

Bandwidth
5 kHz for gains <1,000 and 1 kHz for gains 1,000 and higher.

Slew Rate
3.2 V/µS

Recovery
120 µS to ±0.1% for 10X overload to ±10 V.


Filter

Type
4-freq. 4-pole (standard), 2-freq. 6-pole or 2-freq. 8-pole Butterworth with wideband.

Frequency
4-pole: 4 Hz, 10 Hz, 100 Hz and 1 kHz.
6-pole: 10 Hz and 1 kHz.
8-pole: 10 Hz and 1 kHz.

Noise (Filter)
0.5 mV rms, RTO.

Other
Other filter characteristics and cut offs are available.


Digitizer

Sample
Simultaneous, within ±50 nS channel-to-channel. Droop is less than ±0.005%.

Resolution
16-bits, two's complement.

Sample Rate
Up to 10 kS/s per channel
Up to 10 kS/s

Digitizer Linearity
3 LSB (0.01%)

Continuity
Monotonic to 15 bits.


Calibration

Shunt
Two step Bipolar shunt, 0.5024 mV/V and 0.245 mV/V for 350 Ohm bridge, ±0.1%. For a 120 Ohm bridge, steps are 0.17235 mV/V and 0.08402 mV/V, ±0.1%.

Voltage Substitution
Alternate input for external calibration source. Programmable attenuator with steps of 1, 0.1 and 0.01, ±0.02% accuracy. Output of the attenuator is provided for verification.

Zero Calibration
Amplifier input disconnected and shorted.


Operation

Protocol
Control and data interface is USB 2.0.

Software
Window's driver (Both 32 and 64-bit) provides high-level operating command set. Fully compatible with all implementations of PI660 operating software.

Control Inputs
TTL inputs for Start, Stop and Trigger assert flags in the header of output data that initiate software control operations.

Alarms
Warning and alarm buses may be independent or shared between enclosures and may initiate an output from a digital I/O type module.
Two alarms each with programmable upper and lower limits and persistence checked on each ADC sample.


Data Format

Data Word
16 or 32-bits, 2's complement binary.

Scan Table
Maximum format length is 65,536 samples.

Sample Rates
Multiple sample rates consisting of the highest sample rate divided by binary numbers. Highest sample rate is programmable with 1 uS resolution.


Data Interface

Latency
Processor and scan table dependent, typically less than 5 milliseconds.

Clock Stability
100 ppm over temperature range.

Output Rate
Processor dependent, typically over 5 million 16-bit samples/second.


Connections

Calibration
15-Pin Type D mounted on rear panel. Mating connector supplied.

Control
15-Pin Type D mounted on rear panel. Mating connector supplied.

Synchronization
Category 5, enclosure to enclosure. 2-meter cable supplied.

USB
2-meter cable supplied.


Mechanical

Power (Mechanical)
115 or 230 VAC, 110%, 47 to 63 Hz, 400 Watts.

Operating Temperature (Mechanical)
0 to +50 ºC

Humidity
95% without condensation.

Shock/Vibration
Normal shipping and handling of laboratory instruments.

Width

 View
19 in

Height

 View
5 in

Depth

 View
18 in

Weight
Approximately 25 pounds with all channel modules.

Mounting
Occupies one slot in Series 6000 enclosures.

Connectors
Inputs use two 50-pin Type D connectors. Mating connectors supplied.


Control & Data Processor (CDP) and Operators Workstation (PCCOWU) (Optional)

Input
USB 2.0 ports for up to eight 6000U enclosures. Additional 6000U enclosures accommodated by adding USB expansion cards.


Ordering Information 

Ordering Information
6845-16 - 16-Ch Strain Gage/Transducer DAS (RJ45)


 DOWNLOADS 

Models 6825, 6830 & 6845
(PDF, 400KB)


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