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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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