Campbell 21X Instrukcja Operatora Pobierz pdf (Strona 98)

PATA

[YPE

I

l2

2

2

2

01:

02:

03:

04:

4

'4

4

iFP

FP

05:

06:

07:

08:

09:

PARAM.

NUMBER

DESCRIPTION

Repetitions

Range code

Input

channel

number for

first measurement

Excitation channel

number

Delay

(0.01s)

Excitation

voltage

(millivolts)

Input

location

number for

first

measurement

Multiplier

Offset

Input locatiQns altered:

1

per

measurement

***

9 FULL

BRIDGE

WITH EXCITATION

***

COMPENSATION

FUNCTION

This

instrucfion

is used to

apply an excitation

voltage

and

make two differential

voltage

meas

then

reverse the

polarity

of the

excitation afrd repeat

the

measurements. The

measu are

made on sequential

result

is the voltage

measured on

the

exci

channel

SECTION

9.

INPUT/OUTPUT

INSTRUCTIONS

PARAM.

DATA

NUMBER

TYPE DESCRIPTION

Repetitions

Range code

for Vl

Range code

for

V2

Input channel

number

for

first measurement

Excitation

channel

number

Excitation

voltage

(millivolts)

Input location

number

for

first measurement

Multiplier

Offset

lnput

locations altered:

1

per

measurement

***

10

BATTERY

VOLTAGE

***

FUNCTION

This

instruction reads

the

battery

voltage and

writes it to an input

location. Battery

voltage is

stored

in

volts.

PARAM. DATA

NUMBER

TYPE

DESCRIPTION

01:

4

Input location

Input

locations altered:

1

***

11

107

THERMISTOR

PROBE

***

FUNCTION

This

instruction

applies

a 4

VAC excitation

voltage

to Campbell Scientific's

Model

107

Thermistor

Probe, makes a fast, single-ended

voltage

measurement on the

15mV

range and

then calculates

the temperature

in degrees C

with a

polynomial.

The maximum

polynomial

error

from

-40oC

to

+55oC

is

given

below:

Curve

Fit Error

--

Range

(oC)

2

2

2

2

2

4

4

FP

FP

01:

02:

03:

o4:

05:

06:

07:

08:

09:

channels.

the secondthe second

phannel (Vr)

divided by

the

voltage

measured

Qn

the first

(V1).

lf

V1 is measured

on

(code

5

or

15 in Parameter 2),

then the

is 1000

timesV2A/1.

Al before

number

(1X)

causes the

channelto

be

incremented

with

each

repetition.

When used

as

a

6

wire full

bridge

(Figure

13.5-

1), the

conrtections

are

made

so

that

V.t

is

the

measuremQnt

of the

voltage drop

across the

full

bridge,

and

V2

is the

measurement

of the bridge

output.

Bedause the

excitation

voltage

for

a

full

bridge

meaburement

is usually

in

the

5V range,

the

output

i$ usually

1000

V2A/1 or

millivolts

output

per

volt

excitation.

When used

to measure

a

4

wire

half bridge, the

connectionq

are made

so that

V1 is the

voltage

drop

acrosg

the fixed

resistor

(R),

and

Vr

is the

drop

acrosg

the

sensor

(R.).

As

long as V1 is

not

measurpd on

the 5V

range, the

result is

VrA/1

whic$ equals

Rs/Rf.

The

fast integration time used

in Instruction 11

does

not

provide

rejection of 60

Hz noise. See

example

7.16 for a

method of

measuring the

107 thermistor

where 60 Hz

noise

is a

problem.

-40

to +55

-35

to

+48

Error

(oC)

+1.0

+0.1

9-5

1 2 ... 93 94 95 96 97 98 99 100 101 102 103 ... 190 191

Komentarze do niniejszej Instrukcji

Brak uwag