Isotech 414 User manual

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ANNEALING FURNACE
MODEL 414
T he company is always willing to give technical advice and assistance where appropriate .
Equally, because of the programme of continual development and improvement we reserve the
right to amend or alter characteristics and design without pri or notice. This publication is for
information only.
The NAMAS logo shown in the corner of the pages in this report/handbook is to inform readers
of our accreditation number only and does not imply endorsement by UKAS of the information
herein. Please refer to our Website for our latest UKAS Accredited Schedule.
Isotech North America
158 Brentwood Drive, Unit 4
Colchester, VT 05446
Phone: [phone]
Fax: [phone]
www.isotechna.com
[email protected]

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CONTENTS
PAGE DESCRIPTION
3 - 4 EMC Information
5 Health and Safety Instructions
6Guarantee
7Cautionary Note
8 Unpacking and Initial Inspection
9Specification
10 Introduction
11 Annealing Furnace
12 Operation
13 Commissioning
14 General Layout
15 - 16 Eliminating Contamination During the Calibration of
High Temperature Thermometers
17 Important Note
18 Maintenance

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EMC INFORMATION
This product meets the requirements of the European Directive on Electromagnetic Compatibility
(EM C) 89/336/EEC as amended by EC Directive 92/31/EEC and the European Low Voltage
Directive 73/25/EEC, amended by 93/68/EEC. To ensure emission compliance please ensure that
any serial communications connecting leads (RS232 or RS422(485)) are fully screened.
The product meets the susceptibility requirements of EN 50082-1, criterion B.
Symbol Identification Publication Description
ISO3864 Caution
(Refer to Handbook)
IEC 417 Caution, Hot Surface
ELECTRICAL SAFETY
This equipment must be correctly earthed.
This equipment is a Class 1 Appliance. A protective earth is used to ensure the conductive parts
can not become live in the event of a failure of the insulation.
The protective conductor of the flexible mains cable which is coloured green/yellow MUST be
connected to a suitable earth.
The blue conductor should be connected to Neutral and the Brown conductor to Live (Line).

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Warning: Internal mains voltage hazard. Do not remove the panels.
There are no user serviceable parts inside. Contact your nearest Isotech agent for repair.
Voltage transients on the supply must not exceed 2.5kV.
Conductive pollution, eg. Carbon dust, must be excluded from the apparatus. EN61010 pollution
degrees 2.

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HEALTH AND SAFETY INSTRUCTIONS
1. Read all of this handbook before use.
2. Wear appropriate protective clothing.
3. Operators of this equipment should be adequately trained in the handling of hot and cold
items and liquids.
4. Do not use the apparatus for jobs other than those for whi ch i t wa s designed, ie. the
annealing of thermometers.
5. Do not handle the a p p a ra tus when it is hot (or cold), unless wearing the appropriate
protective clothing and having the necessary training.
6. Do not drill, modify or otherwise change the shape of the apparatus.
7. Do not dismantle the apparatus.
8. Do not use the apparatus outside its recommended temperature range.
9. If cased, do not return the apparatus to its carrying case until the unit has cooled.
10. There are no user serviceable parts inside. Contact your nearest Isotech agent for
repair.
11. Ensure materials, especially flammable material s are kept away from hot parts of the
apparatus, to prevent fire risk.

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GUARANTEE
This instrument has been manufactured to exacting standards and is guaranteed for twelve
months against electrical break-down or mechanical failure caused through defective material
or workmanship, provided the failure is not the result of misuse. In the event of failure
covered by this guarantee, the instrument must be returned, carriage paid, to the supplier for
examination and will be replaced or repaired at our option.
FRAGILE CERAMIC AND/OR GLASS PARTS ARE NOT COVERED BY THIS GUARANTEE
INTERFERENCE WITH, OR FAILURE TO PROPERLY MAINTAIN THIS INSTRUMENT MAY
INVALIDATE THIS GUARANTEE
RECOMMENDATION
The life of your ISOTECH Instrument will be prolonged if regular maintenance and cleaning to
remove general dust and debris is carried out.
Serial No:.............................................
Date:.....................................................
[email protected]
www.isotechna.com
Fax: [phone]
Phone: [phone]
Colchester, VT 05446
158 Brentwood Drive, Unit 4
Isotech North America

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CAUTIONARY NOTE
ISOTECH PRODUCTS ARE INTENDED FOR USE BY TECHNICALLY TRAINED AND
COMPETENT PERSONNEL FAMILIAR WITH GOOD MEASUREMENT PRACTICES.
IT IS EXPECTED THAT PERSONNEL USING THIS EQUIPMENT WILL BE COMPETENT WITH
THE MANAGEMENT OF APPARATUS WHICH MAY BE POWERED OR UNDER EXTREMES
OF TEMPERATURE, AND ARE ABLE TO APPRECIATE THE HAZARDS WHICH MAY BE
ASSOCIATED WITH, AND THE PRECAUTIONS TO BE TAKEN WITH, SUCH EQUIPMENT.

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UNPACKING AND INITIAL INSPECTION
Our packing department uses custom designed packaging to send out your unit, but as accidents
can still happen in transit, you are advised, after unpacking the unit, to inspect it for any sign of
shipping damage, and confirm that your delivery is in accordance with the packing
note. If you find any damage or that part of the delivery is missing notify us or our
agent, and the carrier immediatel y. If the unit is damaged you should keep the
packing for possible insurance assessment.
ELECTRICITY SUPPLY
Before connecting to the electricity supply please familia ri se yo urself with the parts of the
handbook relevant to your model.
Your unit's supply voltage requirement is specified on a plate on the instrument along with the
serial number. All instruments will work on an electricity supply frequency of 50Hz or 60Hz.
The apparatus is provided with an approved power cord . If the plug is not suitable for your
location then the plug should be removed and replaced with an appropriate plug.
Take care to ensure the old plug is disposed safely.
The cable is colour coded as follows:
COLOUR FUNCTION

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Green/yellow Earth (Ground)
Brown Live (line)
Blue Neutral
Please ensure that your unit is correctly connected to the electricity supply.
A Resi d u a l Current Devices sometimes referred to an RCD, ELCB or ground fault detector is
included with the 220/240 V unit.
SPECIFICATION
Voltage : 220/240 V
Power : 1000 W
Supply Frequency : 50/60Hz
Maximum Operating Temperature : 1000°C
Working Volume : 450mm x 50mm dia approx.
Dimensions : Height 880mm
Width 400mm
Depth 620mm
Weight (nett) : 40kg

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MODEL 414 ANNEALING FURNACE INTRODUCTION
One of the duties of a calibration laboratory manager is to ensure that the S.P.R.T.’s used in the
Laboratory are fully annealed and still within specification.
Just using the thermometers within the laboratory will cause work-hardening to take place within
the platinum coil of the SPRT.
Therefore regular annealing is required to ensure the S.P.R.T.’s are in an ideal condition.
In 1990 the new temperature scale ITS-90 specified the use of S.P.R.T.’s up to the Silver point
(961.78°C). At th e se tem p eratures quartz is very porous and in reducing atmospheres the
S.P.R.T.’s can quickly become contaminated.
The Isotech Annealing Furnace offers a safe sol ution for those who wish to anneal S.P.R.T.’s
up to 1000°C.

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ANNEALING FURNACE
The Annealing Furnace has two independent control systems, one for temperature control and
the other for over-temperature protection.
The furnace uses a Euroth e rm 2116 over-temperature cut-off controller. On these models
RESET button is located below the over-temperature controller. The SP value should be set
approximately 50°C higher than the operating controller setting. If this limit should be exceeded
the red push button switch will reset the apparatus once th e fu rnace temperature has fallen
below the SP value.
T o turn o n system power at start up (or as required), it is necessary to depress the red pu sh
button.
Altering the Alarm Temperature, (Setpoint)
1. Switch the unit on.
2. The controller will briefly show its software version before displaying an indication of the
f u
r n
a
ce
t e
m
p
e r
a t
u r
e.

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3. Momentarily press eith e r the UP or DOWN key once to display the alarm setpoint This
value should be set to 50°C approximately above the operating controller temperature.
4. To alter the value press and hold the UP key to raise the value or the DOWN key to lower
the value.
5. The display will return to show the nominal furnace temperature when no key is pressed
for 0.5 second.

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OPERATION
Altering the Furnace Temperature, (Setpoint)
1. Switch the unit on. The power switch is located on the power entry module, front panel.
NOTE: Do not switch the unit off until the block has cooled. Preferably below 200°C but not
above 600°C or damage to the controller may occur.
2. T
h
e
c
o
n
tr
ol
le
r
w
ill briefly show its software version before displaying an indication of the block
temperature.
3. Momentarily press either the UP or DOWN key on ce to display the setpoint (desired
temperature).

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4. To alter the value press and hold the UP key to raise the value or the DOWN key to lower
the value.
5. The display will return to show the nominal block temperature when no key is pressed
for 0.5 second.
The other controller functions are hidden from the operator. The values are pre-set and
should not be changed.
COMMISSIONING
Connect the 3 core supply cable to a plug capable of passing up to 13 amps.
Plug in, and switch on. Press the red reset button; this will energise the apparatus.
T he rate of change of temperature for the ceramic furnace liner at low temperature must be
controlled, and for this reason the furnace controller has been pre-programmed to warm up
sl owly to its working temperature. The parameters used to effect this control are not directl y
accessible, for safety reasons.
Set the main controller to 100°C and the over-temperature controller to 150°C.
When the main controller has stabilised. Reduce the over-temperature controllers setting until
the relay operates and the apparatus has switched off.
The apparatus is now ready for use.
A l l
o t h e r
controll
er functions are hidden from the operator. The values are preset and should not be changed.
The annealing/pre-heating furnace controller has been pre-set to produce a slow change in
temperature, in line with the hea ti ng and cooling rates recommended for annealing of
thermometers. Do not over-ride the control settings.

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The recrystallised alumina liner has a closed end and thermometers may be placed directly into
the liner for annealing. However, for high temperature applications, the use of a supplementary
kit, is recommended, as described later.
ELIMINATING CONTAMINATION DURING THE CALIBRATION OF
HIGH TEMPERATURE THERMOMETERS
It is quite feasible to heat a high temperature thermometer to 1000°C and return it to ambient
temperature without altering the water triple point resistance value by mo re than 0.5mK
equivalent.
Instructions in the Isotech 962 and 96178 thermometer handbooks explain how to handle and
keep clean the thermometers. It is imperative that procedures are fo l l owe d b ecause
contaminants can penetrate and pass through physically-intact quartz sheaths at temperatures
above 800°C.
The completed assembly is depicted below:

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AIRFLOW
MACHINED
CERAMIC
PLUG
SMALL
QUARTZ
TUBE
FIXED
ALUMINA
FURNACE
LINER
QUARTZ
WOOL
KAOWOOL
PAD

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Air percolates through the quartz wool oxidising any pollutantsand rendering them harmless and
unable to penetrate the quartz sheath of the thermometer.
The co m bi n ation of air-flow and positioning ensures that thermometers will not become
contaminated at high temperature.
An air pump is fitted internally and runs continuously. The supplied quartz tube is connected to
the air outlet via the plastic hose. Ensure that the metal pipe fitting is pushed fully into the air
outlet, a sharp click is heard when the components co rre ctl y mate. The air flow rate can be
adjusted from the front panel control.

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IMPORTANT NOTE
Since the calibration of sensorsat high temperatures can be fraught with difficulties, if any doubt
exists, please consult Isotech for advice before embarki ng on any exercise in which there is a
risk of contamination of the sensors you are trying to calibrate.

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MAINTENANCE
Unless damaged in transit, the apparatus should operate for many years without maintenance
or fault.
It has been common practice in the past to list a number of possible fault modes and corrective
actions. However, our experience suggests that the very low incidence of failure almost implies
modes not encountered previously and, therefore, not easy to envisage before-hand.
Therefore, we now prefer to work differently. With international communications so good these
days, if anything goes wrong with the apparatus, or you need any other after sales service,
please contact Isotech by telephone, fax or e-mail (or the agent from whom you purchased the
apparatus). On our help-line we are anxious to serve you and will swiftly be able to help you
solve your problem, or deal with a technical enquiry.