Fluke 80t-150 User manual

LL

(6)

Instruction

Manual

Model

80T-150

Temperature

Probe

INTRODUCTION

The

Model

80T-150

Temperature

Probe

is

a

self-contain-

ed

temperature-to-voltage

converter.

И

is

designed

to

provide

a

direct

temperature

reading

when

connected

to

any

high

impedance

voltmeter

that

is

capable

of

1

mV

resolution,

and

at

least

a

300

count

full-scale

readout

capability.

Two

temperature

ranges

are

provided,

and

either

can

be

jumper

selected;

-58

to

+302°F

or

-50

to

+150°C.

The

unit

is

housed

in

two

separate

assemblies;

atempera-

ture

probe

and

a

temperature-to-voltage

converter.

The

probe

contains

the

temperature

sensing

element

and

is

electrically

connected

to

the

temperature-to-voltage

converter

through

a

46-inch

shielded

cable.

Two

banana

plugs

with

standard

0.75

inch

spacing

are

provided

for

connecting

the

80T-150

to

the

voltmeter.

Operating

power

for

the

80T-150

15

derived

from

two

internal

batteries.

Typically,

they

will

provide

up

to

1000

hours

of

continuous

operation

before

replacement

is

necessary.

An

ON/OFF

switch

is

provided

on

the

temperature-to-voltage

converter

to

allow

battery

conservation

when

the

unit

is

not

in

use.

Temperature

is

measured

by

exposing

the

probe

tip

directly

to

the

material

to

be

measured

(liquid,

gas

or

solid).

A

direct

temperature

reading

is

displayed

on

the

voltmeter.

SPECIFICATIONS

The

80T-150

will

achieve

rated

accuracy

when

used

with

any

0.25%

DVM

which

has

an

input

impedance

of

>

1

MO.

Specifications

for

the

80T-150

are

given

in

Table

1.

80T-150

OPERATING

NOTES

The

following

paragraphs

are

intended

to

familiarize

the

operator

with

the

80T-150,

as

shown

in

Figure

1.

They

should

be

read

before

attempting

to

operate

the

probe.

Probe

Limitations

The

80T-150

probe

is

constructed

of

a

highly

durable

plastic

and

is

suitable

for

measuring

the

temperature

of

liquids,

gases

and

solid

surfaces

up

to

150°C.

When

measuring

temperature,

observe

the

following

pre-

cautions

to

prevent

damage

to

the

probe:

а

Do

not

expose

the

probe

end

(probe

tip

plus

~2

inches

of

probe

body)

to

temperatures

in

excess

of

+150

С.

The remainder

of

the

probe

body

should

not

be

exposed

to

temperatures

above

+70

С.

b.

For

liquid

measurements,

recommended

applica-

tions

range

from

water,

lubricants

and

fuels

to

most

solvents.

Liquids

as

shallow

as

4”

can

be

measured

since

the

temperature

sensor

is

in

the

probe

tip.

CAUTION

Long

term

exposure

of

the

probe

to

corrosive

environments

will

result

in

pitting

and

deteri-

oration

of

the

aluminum

probe

tip.

Temperature

Scale

The

80T-150

is

capable

of

providing

temperature

mea-

surements

in

°C

or

°F.

See

decal

opposite

power

switch

for

assigned

temperature

scale.

Instructions

for

changing

temperature

scale

are

given

later

under

General

Mainten-

ance.

Table

1.

Specifications

ELECTRICAL

Range

(field

selectable.

. .

50°С

to

+150°C

or

—58

F

by

internal

jumpers).

to

+302°F

Accuracy

1159106

+35°C

7

Best)

їн

М

ambient

+1

C

MS

FIO

C

ton

OLG,

decreasing

linearly

to

+

oe

(5.4°F)

at

-50°C

and

+150°C

0°C

to

+15°C

and

+35°C

to

+50°

ambient

Add

1°C

(1.8°F)

to

above

Sensitivity

(807—150

output)

1

mV

de/

°C

or

1

mV

de/

°F

350V

dc

or

peak

ac

5.5

seconds

to

settle

within

2°

Voltage

Standoff

Settling

Time

for

a

50°

change.

Overall

Length

Power.

. .

Two

internal

disposable

batteries

(1.5V,

Size

№”)

Output

Termination....

GENERAL

100

gm

(3.5

oz.)

1.33

meters

(52.5

in.)

1000

hours

continuous

use

Standard

0.75“

spaced

double

banana

plug

ENVIRONMENTAL

Entire

Unit

Storage

Operating

Altitude

<50000

ft.

<10000

ft.

—40

to

+70°C

О

to

+50°C

80%

non-

condensing

Temperature

Humidity

Application

Force

20

pounds

max.

(Probe

tip-to-measurements

surface)

80T-150

TEMPERATURE-

TO-VOLTAGE

CONVERTER

POWER

SWITCH

Va

ON/OFF

BANANA

PLUGS

(0.75

”

SPACING)

PROBE

TIP

ЕЕ]

PROBE

CABLE

PROBE

BODY

Figure

1.

80T-150

Features

Error

Sources

When

the

probe

пр

15

applied

to

a

solid

surface

it

draws

or

sinks

heat

from

the

surface.

Therefore,

if

the

measured

surface

has

a

low

mass

(е.р.,

a

transistor

case),

the

in-

dicated

temperature

may

be

lower

than

the

actual

temperature.

Similarly,

a

steady-state

error

or

gradient

exists

between

the

measured

surface

and

the

sensing

device

in

the

probe

tip.

This

15

due

to

the

flow

of

heat

from

the

measurement

surface

to

the

probe

body.

The

effect

of

the

steady-state

error

increases

as

the

differential

between

ambient

and

surface

temperature

increases.

To

determine

the

actual

surface

temperature

of

a

device,

both

the

heat-sinking

and

steady-state

errors

must

be

considered.

The

correction

curve

given

in

Figure

2

approximates

the

effect

of

both

error

sources

on

TO-3,

TO-5

and

TO-18

transistor

cases.

son

HH

naa

зи

Й

|

ГТА

ви

ЕД

|

4

Ӯ

|]

um

i

=

`

DEGREES

ABOVE

AMBIENT

(°C)

в

u

в

y

4”.

r

4

в

[1

в

1

в

Ц

INITIAL

SURFACE

TEMPERATURE

IN

INDICATED

SURFACE

TEMPERATURE

DEGREES

ABOVE

AMBIENT

Figure

2.

Initial

Case

Temperature

Above

Ambient

vs.

Meter

Reading

Above

Ambient

RF

signals

applied

to

the

80T-150

probe

tip

can

also

cause

errors

in

temperature

measurement.

Figure

3

defines

the

rf

signal

limits

that

can

be

tolerated

without

degrading

measurement

accuracy.

AN

m

'

da

ma

ай

ва

ма

|

aa

Figure

3.

Maximum

Signal

RF

Limits

(Vrms)

at

Probe

Tip

OPERATION

Use

the

following

procedure

to

operate

the

80T-150

probe:

a.

Connect

the

banana

plugs

on

the

80T-150

to

the

input

terminals

of

a

high

impedance

voltmeter.

Observe

polarity.

b.

Select

a

dc

voltage

range

that

will

provide

at

least

1

mV

resolution

(1

mV/degree),

and

a

full

scale

readout

that

will

encompass

the

expected

temperature.

The

2V

range

of

a

3%

digit

DVM

is

adequate.

Ignore

readings

of

less

than

1°

when

a

more

sensitive

DVM

is

used.

с:

Set

the

80T-150

power

switch

to

ON

and

energize

the

voltmeter.

d.

Firmly

touch

the

probe

tip

to

the

surface

to

Бе

measured,

or

expose

it

to

a

liquid

or

gas.

The

volt-

meter

will

display

the

temperature

in

degrees.

Vary

probe

angle

and

pressure

when

measuring

solid

surface

temperatures;

the

highest

stabilized

reading

will

be

the

most

accurate.

CAUTION

The

force

exerted

on

the

probe

tip

should

not

exceed

20

pounds.

THEORY

OF

OPERATION

The

Model

80T-150

utilizes

the

negative

temperature

coefficient

of

a

semiconductor

(P-N)

junction

to

measure

temperature.

The

PN

junction

is

thermally

integrated

into

the

probe

tip

and

comprises

one

leg

of

a

bridge

circuit

as

shown

in

simplified

circuit

diagram

section

of

Figure

4.

Two

1.5V

batteries

are

used

to

power

both

the

bridge

circuit

and

operational

amplifier

U2.

Since

the

bridge

must

be

balanced

to

provide

0°C

and

0°

Е

indica-

tions,

separate

range

or

temperature

scale

resistors

RA

and

RB

are

included

in

the

bridge

circuit.

When

RB

is

shorted,

the

°C

scale

is

selected

and

the

bridge

is

calibrat-

ed

by

R2

to

null

at

0°C.

Conversely,

when

КВ

is

open,

the

02

Е

scale

is

selected

and

the

bridge

is

calibrated

by

R2

to

null

at

0"

Е.

Deviations

above

and

below

0°

provide

a

bridge

output

of

approximately

2.45

mV/*C.

Figure

4.

Simplified

Circuit

Diagram

Operational

amplifier

U2

is

used

to

measure

the

bridge

output

and

scale

itto

a

|

mV/degree

signal.

Since

the

°C

and

the

°F

scale

are

sloped

differently,

the

scale

for

U2

must

be

matched

with

the

scale

selected

for

the

bridge

circuit.

Shorting

resistor

RD

selects

the

°C

scale.

Con-

versely,

when

КО

is

open

the

°

F

scale

is

selected.

Resistor

К4

calibrates

both

scales.

The

output

voltage

used

to

drive

the

external

voltmeter

is

taken

from

the

output

of

U2(P2)

and

the

reference

side

of

the

bridge

(P1).

Since

U2

is

operating

as

an

inverting

amplifier,

its

output

is

used

as

the

low

input

to

the

volt-

meter.

This

enables

the

voltmeter

to

display

an

increase

in

temperature

as

an

increase

in

voltage.

GENERAL

MAINTENANCE

Access

Information

The

battery,

the

temperature

scale

jumpers

and

the

calibration

pots

are

located

on

the

interior

of

the

temp-

80T-150

erature-to-voltage

converter

assembly.

Access

to

these

locations

is

accomplished

by

removing

the

three

screws

from

the

bottom

side

of

the

assembly

and

removing

the

plastic

box.

Battery

Replacement

The

807-150

uses

two

1.5

volt,

size

N,

alkaline

batteries.

They

provide

a

useful

operating

life

of

=1000

hours.

To

replace

the

batteries

pull

the

old

ones

out

and

press

the

new

ones

into

the

battery

holders.

Match

polarity

mark-

ed

on

the

pcb.

Mercury

or

equivalent

N-size

batteries

may

be

installed

in

the

80T-150.

Temperature

Scale

Jumpers,

°C

or

°F

The

jumper

locations

for

selecting

either

the

°C

or

°F

temperature

scale

are

shown

in

Figure

5.

The

absence

of

jumpers

at

both

points

indicates

selection

of

the

°F

scale.

The

presence

of

solder

bridges

at

both

points

indicates

selection

of

the

°C

scale.

Under

no

circumstances

should

one

point

be

open

while

the

other

is

bridged.

TEMPERATURE

SCALE

JUMPERS

80T-3001

Figure

5.

Temperature

Scale

Jumpers

PERFORMANCE

TEST

Complete

the

calibration

procedure

without

opening,

the

temperature-to-voltage

converter

assembly

and

with-

out

making

any

calibration

adjustments.

Observe

the

readings

given

in

[brackets].

Other

readings

are

for

cal-

ibration

only.

CALIBRATION

A

calibration

cycle

of

|

year

is

recommended

to

maintain

the

unit

within

the

specifications

given

earlier.

The

equip-

ment

required

for

calibration

is

listed

in

Table

2.

NOTE

Values

given

in

brackets

apply

to

the

Per-

formance

Test.

80T-150

a.

Access

the

interior

of

the

temperature-to-voltage

NOTE

converter.

If

the

unit

is

calibrated

on

the?

Е

scale,

inter-

action

will

occur

between

adjustments

R2

and

R4.

Repeat

steps

d,

e,

f

and

g

until

read-

ings

are

obtainable

without

adjustment.

b.

Determine

the

selected

temperature

(°C

or

°F).

See

marking

on

bottom

cover

decal.

c.

Connect

the

80T-150

to

a

DVM

and

select

the

Table

2.

Test

Equipment

Requirements

100

mV

ас

range

(10

uV

resolution).

Instrument

Minimum

Use

Recommended

Type

Specifications

Model

а.

Turn

the

80T-150

power

switch

to

ON

and

immerse

Mercury

0.1°C

i

Princo

Model

the

probe

tip

=2

inches

into

a

thermometer

moni-

Thermometer

Resolution

SAMA-CP45

tored

0°C

bath.

Allow

the

DVM

reading

to

stabil-

Dewar

Flask

1-pint

capacity

Thermos

ize

(2230

seconds).

and

Cap

(for

¡ce

bath)

Bottle

Metal

or

1-pint

capacity

Suitable

for

y

e

4

я

Glass

Container

boiling

water

e.

Adjust

R2

(see

Figure

6.)

to

obtain

the

appropriate

S

DVM

reading:

Digital

Volt

100

mV

range

Fluke

Model

У

Meter

with

10

uV

8600A

°C

0.00#0.05

mV

de

[0+2

mV

dc]

2E

320501

мас

[32:04

то

М

de]

If

necessary,

additional

cw

range

can

be

added

to

R2

by

adding

a

solder

bridge

across

E8

and

E9

as

shown

in

Figure

5.

Resolution

1000

mV

range

with

100

uV

Resolution

PROBE

REPLACEMENT

f.

Immerse

the

probe

tip

approximately

2

inches

into

a

70

to

100°C

bath

and

allow

the

DVM

reading

to

A

probe

kit

(80T-150-7001k)

is

available

for

replacing

stabilize.

Change

DVM

range,

if

necessary,

for

damaged

or

defective

probes.

The

kit

includes

a

probe

°F

calibration.

and

cable

assembly,

four

metal

film

resistors

(R3),

and

an

installation

and

calibration instruction

sheet.

р.

Adjust

R4

to

obtain

а

DVM

reading

which

agrees

LIST

OF

REPLACEABLE

PARTS

with

the

bath

temperature

(BT)

as

monitored

by

a

mercury

thermometer.

Component

location

drawings

and

a

list

of

replaceable

ЗОЎ

BA<E0.05

mV

дет,

[BTÆ2

mMmVide]

parts

are

shown

in

Figure

6.

When

ordering

parts,

рго-

Cy

BTEO

mV

de®

ВУСА

ОУ

de]

vide

description,

Fluke

ра

and

quantity

required.

NOTES:

Sensing

Probe

and

Cable

Assembly,

80T-150-7001

K

(includes

selected

resistor

R3)

Temperature-to-Voltage

Converter

PCB

Assembly

(order

80T-150)

Battery,

Alkaline,

1.5V,

size

N

Socket,

1-pin

Plugs,

banana

Resistor,

selected

(supplied

with

A1

Assy)

Button,

switch,

green

(not

shown)

Housing,

bottom

(not

shown)

Housing,

top

(not

shown)

Shock

absorbers

(not

shown)

Decal,

bottom

(not

shown)

Decal,

top

(not

shown)

Screw

(not

shown)

[7

Part

of

resistor

network

U1

2:

Unless

otherwise

noted,

all

capacitance

is

in

ur

and

all

resistance

is

in

ohms.

All

voltages

measured

with

respect

to

TP1.

431023

478735

343285

352716

432575

527747

527739

428441

534792

534784

183574

80T-150

80T-1601

Temperature-to-Voltage

Converter

PCB

Assembly

R3

SELECT

J2

Cap,

disc,

0.01

uF

+20%,

100V

ас

Cap,

Ta,

2.2

uF

+20%,

20V

de

Res,

metal

film,

1.62k

+1%,

1/8W

Res,

variable,

2k,

1/2W

See

Final

Assembly

Res,

variable,

50k

1/2W

Switch,

slide

Resistor

Network

Resistor

Network

IC,

linear

op

amp

Diode,

zener,

1.22V

de

Contact,

Battery

Figure

7.

80T-150

Temperature

Probe

Schematic

5

149153

161927

282697

226076

225417

393629

616615

616656

418913

452771

477463

80T-1201

www.manualsplus.com

P/N

433565

|

June

1976

1020806

Кем

4

8/82

Litho

in

U.S.A.

01982,

John

Fluke

Mfg.

Co.,

Inc.,

all

rights

reserved.

Litho

in

U.S.A.

John

Fluke

Mfg.

Co.,

Inc.

/

P.O.

Box

С9090

/

Everett,

WA

98206

Fluke 80T-150 User manual

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