Campbell CR800 Especificações descarregar pdf (Página 51)

CR800 and CR850 Overview

OV6. Specifications

PROGRAM EXECUTION RATE

10 ms to 30 min. @ 10 ms increments

ANALOG INPUTS

3 differential (DF) or 6 single-ended (SE) individually

configured. Channel expansion provided by AM16/32

and AM25T multiplexers.

RANGES and RESOLUTION: Basic resolution

(Basic Res) is the A/D resolution of a single

conversion. Resolution of DF measurements

with input reversal is half the Basic Res.

Input Referred Noise Voltage

Input DF Basic

Range (mV)

Res (µV)

±5000 667 1333

±2500 333 667

±250 33.3 66.7

±25 3.33 6.7

±7.5 1.0 2.0

±2.5 0.33 0.67

Range overhead of ~9% exists on all ranges to guarantee

that full-scale values will not cause over-range.

Resolution of DF measurements with input reversal.

ACCURACY

±(0.06% of reading + offset), 0° to 40°C

±(0.12% of reading + offset), -25° to 50°C

±(0.18% of reading + offset), -55° to 85°C

The sensor and measurement noise are not included and

the offsets are the following:

Offset for DF w/input reversal = 1.5·Basic Res + 1.0 µV

Offset for DF w/o input reversal = 3·Basic Res + 2.0 µV

Offset for SE = 3·Basic Res + 3.0 µV

INPUT NOISE VOLTAGE: For DF measurements

with input reversal on ±2.5 mV input range; digital

resolution dominates for higher ranges.

250 µs Integration: 0.34 µV RMS

50/60 Hz Integration: 0.19 µV RMS

MINIMUM TIME BETWEEN VOLTAGE

MEASUREMENTS: Includes the measurement time

and conversion to engineering units. For voltage

measurements, the CR800-series integrates the

input signal for 0.25 ms or a full 16.66 ms or 20 ms

line cycle for 50/60 Hz noise rejection. DF mea-

surements with input reversal incorporate two

integrations with reversed input polarities to reduce

thermal offset and common mode errors and there-

fore take twice as long.

250 µs Analog Integration: ~1 ms SE

1/60 Hz Analog Integration: ~20 ms SE

1/50 Hz Analog Integration: ~25 ms SE

COMMON MODE RANGE: ±5 V

DC COMMON MODE REJECTION: >100 dB

NORMAL MODE REJECTION: 70 dB @ 60 Hz

when using 60 Hz rejection

SUSTAINED INPUT VOLTAGE W/O DAMAGE:

±16 Vdc max.

INPUT CURRENT: ±1 nA typical, ±6 nA max.

@ 50°C; ±90 nA @ 85°C

INPUT RESISTANCE: 20 Gohms typical

ACCURACY OF BUILT-IN REFERENCE JUNCTION

THERMISTOR (for thermocouple measurements):

±0.

3°C, -25° to 50°C

±0.8°C, -55° to 85°C (-XT only)

ANALOG OUTPUTS

2 switched voltage, active only during measurement,

one at a time.

RANGE AND RESOLUTION: Voltage outputs program-

mable between ±2.5 V with 0.67 mV resolution.

ACCURACY: ±(0.06% of setting + 0.8 mV), 0° to 40°C

±(0.12% of setting + 0.8 mV), -25° to 50°C

±(0.18% of setting + 0.8 mV), -55° to 85°C (-XT only)

CURRENT SOURCING/SINKING: ±25 mA

RESISTANCE MEASUREMENTS

MEASUREMENT TYPES: The CR800-series provides

ratiometric measurements of 4- and 6-wire full

bridges, and 2-, 3-, and 4-wire half bridges.

Precise, dual polarity excitation using any of the

3 switched voltage excitations eliminates dc errors.

RATIO ACCURACY

: Assuming excitation voltage of

at least 1000 mV, not including bridge resistor error.

±(0.04% of voltage reading + offset)/V

The sensor and measurement noise are not included and

the offsets are the following:

Offset for DF w/input reversal = 1.5·Basic Res + 1.0 µV

Offset for DF w/o input reversal = 3·Basic Res + 2.0 µV

Offset for SE = 3·Basic Res + 3.0 µV

Offset values are reduced by a factor of 2 when

excitation reversal is used.

PERIOD AVERAGING MEASUREMENTS

The average period for a single cycle is determined by

measuring the average duration of a specified number

of cycles. The period resolution is 192 ns divided by

the specified number of cycles to be measured; the

period accuracy is ±(0.01% of reading + resolution).

Any of the 6 SE analog inputs can be used for period

averaging. Signal limiting are typically required for the

SE analog channel.

INPUT FREQUENCY RANGE:

Input Signal (peak to peak)

Min. Max

Range Min Max Pulse W. Freq.

±2500 mV 500 mV 10 V 2.5 µs 200 kHz

±250 mV 10 mV 2 V 10 µs 50 kHz

±25 mV 5 mV 2 V 62 µs 8 kHz

±2.5 mV 2 mV 2 V 100 µs 5 kHz

The signal is centered at the datalogger ground.

The maximum frequency = 1/(Twice Minimum Pulse Width)

for 50% of duty cycle signals.

PULSE COUNTERS

Two 24-bit inputs selectable for switch closure, high

frequency pulse, or low-level ac.

MAXIMUM COUNTS PER SCAN: 16.7x10

SWITCH CLOSURE MODE:

Minimum Switch Closed Time: 5 ms

Minimum Switch Open Time: 6 ms

Max. Bounce Time: 1 ms open w/o being counted

HIGH FREQUENCY PULSE MODE:

Maximum Input Frequency: 250 kHz

Maximum Input Voltage: ±20 V

Voltage Thresholds: Count upon transition from

below 0.9 V to above 2.2 V after input filter with

1.2 µs time constant.

LOW LEVEL AC MODE: Internal ac coupling removes

dc offsets up to ±0.5 V.

Input Hysteresis: 16 mV @ 1 Hz

Maximum ac Input Voltage: ±20 V

Minimum ac Input Voltage:

Sine wave (mV RMS) Range (Hz)

20 1.0 to 20

200 0.5 to 200

2000 0.3 to 10,000

5000 0.3 to 20,000

DIGITAL I/O PORTS

4 ports software selectable, as binary inputs or control

outputs. They also provide edge timing, subroutine

interrupts/wake up, switch closure pulse counting, high

frequency pulse counting, asynchronous communica-

tions (UART), SDI-12 communications, and SDM

communications.

HIGH FREQUENCY MAX: 400 kHz

SWITCH CLOSURE FREQUENCY MAX: 150 Hz

OUTPUT VOLTAGES (no load): high 5.0 V ±0.1 V;

low <0.1

OUTPUT RESISTANCE: 330 ohms

INPUT STATE: high 3.8 to 5.3 V; low -0.3 to 1.2 V

INPUT HYSTERISIS: 1.4 V

INPUT RESISTANCE: 100 kohms

SWITCHED 12 V

One independent 12 V unregulated sources switched

on and off under program control. Thermal fuse hold

current = 900 mA @ 20°C, 650 mA @ 50°C, 360 mA

@ 85°C.

SDI-12 INTERFACE SUPPORT

Control ports 1 and 3 may be configured for SDI-12

asynchronous communications. Up to ten SDI-12

sensors are supported per port. It meets SDI-12

Standard version 1.3 for datalogger mode.

CE COMPLIANCE

STANDARD(S) TO WHICH CONFORMITY IS

DECLARED: IEC61326:2002

CPU AND INTERFACE

PROCESSOR: Renesas H8S 2322 (16-bit CPU with

32-bit internal core)

MEMORY: 2 Mbytes of Flash for operating system;

4 Mbytes of battery-backed SRAM for CPU usage,

program storage and data storage

SERIAL INTERFACES: CS I/O port is used to

interface with Campbell Scientific peripherals;

RS-232 port is for computer or non-CSI modem

connection.

BAUD RATES: Selectable from 300 bps to 115.2 kbps.

ASCII protocol is

one start bit, one stop bit, eight

data bits, and no parity.

CLOCK ACCURACY: ±3 min. per year

SYSTEM POWER REQUIREMENTS

VOLTAGE: 9.6 to 16 Vdc

TYPICAL CURRENT DRAIN:

Sleep Mode: ~0.6 mA

1 Hz Scan

(60 Hz rejection)

w/RS-232 communication: 19 mA

w/o RS-232 communication: 4.2 mA

1 Hz Scan

(250 µs integration)

w/RS-232 communication: 16.7 mA

w/o RS-232 communication: 1 mA

100 Hz Scan

(250 µs integration)

w/RS-232 communication: 27.6 mA

w/o RS-232 communication: 16.2 mA

CR1000KD OR CR850'S ON-BOARD

KEYBOARD DISPLAY CURRENT DRAIN:

Inactive: negligible

Active w/o backlight: 7 mA

Active w/backlight: 100 mA

EXTERNAL BATTERIES: 12 Vdc nominal; reverse

polarity protected.

PHYSICAL SPECIFICATIONS

DIMENSIONS: 9.5" x 4.1" x 2" (24.1 x 10.4 x 5.1 cm);

additional clearance required for serial cable and

sensor leads.

WEIGHT: 1.5 lbs (0.7 kg)

WARRANTY

Three years against defects in materials and

workmanship.

Electrical specifications are valid over a -25° to +50°C range unless otherwise specified; non-condensing environment required. To maintain

electrical specifications, Campbell Scientific recommends recalibrating dataloggers every two years. We recommend that you confirm sys-

tem configuration and critical specifications with Campbell Scientific before purchase.

OV-43

1 2 ... 46 47 48 49 50 51 52 53 54 55 56 ... 323 324

Comentários a estes Manuais

Sem comentários

Campbell CR800 Especificações Página 51

Comentários a estes Manuais

Manuais e produtos relacionados com Medição, teste e controlo Campbell CR800