AST A250C+ FO PL User manual

AST A250C+ FO PL
USER MANUAL
Accurate Sensors Technologies
Non-contact Infrared Pyrometers
We measure accurate temperature in extreme conditions
AST - Accurate Sensors Technologies
Misgav Industrial Park
Tel: [phone], Fax: [phone]
Email: [e-mail]
Web: www.accuratesensors.com
, Misgav 20173, Israel

Index
1. Chapter - 1
General information
2. Chapter - 2 ....................................................................................................................... 2
Introduction
2.1 Product Key Features, Application and Range
2.2 Technical specification
2.3 Optics
3. Chapter - 3 ....................................................................................................................... 6
Basics & Installation of Pyrometer
3.1 Basics of Infrared temperature measurement of an object
3.2 Installation
3.3 Location Selection
3.4 Mechanical Accessories
3.5 Electrical Installation
4. Chapter - 4 ....................................................................................................................... 14
Setting at the Instruments
4.1 Operation
4.2 Key Descriptions
4.3 Adjustable Parameters
4.4 Other Parameters
5. Chapter - 5 ....................................................................................................................... 17
Software installation
4.1 Installation
4.2 Parameters in main screen
6. Chapter - 6 ....................................................................................................................... 24
Maintenance
7. Chapter -7 ....................................................................................................................... 25
Serial communication protocol
8. Appendix B ....................................................................................................................... 30
9. Appendix C ....................................................................................................................... 32
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Congratulations on choosing this high quality and highly efficient AST pyrometer for non contact temperature
measurement.
Please read this user manual carefully, step by step, including all notes of security, operation and maintenance
before installing the pyrometer. This manual contains all the necessary instructions for set up and operation of the
pyrometer. This section provides an overview about important safety regulations.
Some Important Safety Regulations Given Below
1. Safety Precaution
Each person working with pyrometer must read the user manual before operation. The pyrometer has only to be
used for the purpose described in manual. The pyrometer works only with a potential free low voltage of range
24VDC. This voltage is not harmful for user. The pyrometer may contain harmful material and hence it should not be
disposed of with normal waste.
2. Packaging and Storage
Always use a shock proof package for shipment of pyrometer. It should be sealed to protect it against humidity. Also
protect the lens of pyrometer with cover. They should be stored at the temperature range from -20°C to 70°C.
3. Limit of Liability and Warranty
All general information and notes for handling, maintenance and cleaning of this instrument are offered according to
the best of our knowledge and experience.
AST reserves the right to revise this document and to make change from time to time in the content hereof without
obligation to notify any person or persons of such revisions or changes
AST instruments have a warranty of two year from the invoice date. This warranty covers manufacturing defects and
faults which arise during operation only if they are the results of defects caused by AST.
AST does not accept liability for any damages or losses which might occur, including consequential damages and
financial losses, as a result of use of the instrument.
4. Copyright
All rights reserved . this document may contain proprietary information and shall be respected as a proprietary
document to AST with permission for review and usage given only to the rightful owner of the instrument with which
this document is associated.
Chapter - 1
General Information

Chapter - 2
Introduction
AST A250C+ FO PL is digital two color pyrometer which uses ratio of two adjacent wavelengths for temperature
measurement to target object. They are specially designed highly accurate digital pyrometers to provide high
performance and low maintenance of non contact temperature measurement in demanding industrial
environment.
2.1 Application and Range
The AST A250C+ FO PL pyrometers are especially designed for industrial purposes. They are suitable for high
temperature measurement ranging from 350°C to 1350°C.
These pyrometers have solid body in stainless steel housing, which provides high operation safety even in rough
industrial environment, and large variety of focusable optics which can be easily used in all industrial areas.
These pyrometers have OLED display which shows temperature and provides menu selection via parameterizaion
keys. AST A250C+ FO PL have a fast response time of 20msec. The Pyrometer provided RS-485 for long distance
communication between pyrometer & PC software Infrasoft. Response time, emissivity, sub-range and peak picker
selection can be preset ex-works or adjustable through available software.
The AST A250C+ FO PL pyrometers are suitable for industrial purpose due to following advantages :
lMeasurement of temperature is not affected by emissivity of object.
lMeasurement of object temperature is possible where dust, moisture & other contaminants are present in
surrounding environment.
lThe measuring object can be smaller than spot size.
lThe pyrometer can be switched between 1-colour & 2-colour mode.
Temperature measurement can be taken in any of the following modes:
1. Single colour mode.
2. Two colour mode.
Single Colour Mode : Single colour mode is best for measuring the temperature of target object in areas where no
sighting obstacle is present between the target object and the pyrometer. Sighting obstacle can be any solid item,
gaseous particles, smoke and dust etc. This mode is very useful where target object completely fills the spot size.
Two Colour Mode : The basic concept of two colour mode is temperature measurement of the target object is done
by the ratio of two separate and overlapping of infrared bands. Two sensors are used in this type of pyrometer.
2.2 Operational Theory for 2-colour sensors
Accurate and repeatable temperature measurement is possible with the two colour ratio technology that does not
depend on emissivity of object. Basically a 2 colour sensor determines temperature from the ratio of radiated
energies in two separate wavelength bands (2 different colours).
Advantages of two colour pyrometer over single colour pyrometer which makes it suitable for industrial usage are as
follows:
lMeasurement of temperature is not affected by emissivity of object.
lMeasurement of object temperature is possible where dust, moisture and other contaminants are present
in surrounding environment.
lThe measuring object can be smaller than the spot size.
lThe pyrometer can be switched between 1-colour and 2-colour mode.
lThe spot is partially blocked or obscured.
Product Key Features,
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2.2.1 Measurement of temperature is not affected by low or changing emissivity values
If the value of emissivity in both colours (wavelengths) are same as like for the black body (where emissivity =1.0)
or for grey body where emissivity is less than 1.0 but a constant number and the emissivity of the target would not
get influenced. But actually grey body does not exist in nature. The emissivity of all real objects changes with
temperature and wavelength at variable degrees, depending on the material. 2 colour pyrometer is more accurate
than single colour pyrometer when emissivity is uncertain or changing but emissivity should change by same factor
in both wavelength bands. Accuracy of result measurement is dependent on the type of material being measured
and the application for which it is used.
2.2.2 The measuring object is smaller than spot size
If the target object is moving or it is smaller than the spot size, the amount of radiated energy is also reduced. But
the ratio of energies is unaffected and hence the measured temperature remains accurate.
2.2.3 The spot is partially blocked or obscured
The energy emitted from a target is usually reduced when target object is being blocked or some portion of the
optical head is blocked. But the ratio of the energies is not affected and hence the measured temperature remains
extremely accurate.
2 colour pyrometer is better than 1 or single colour in the following conditions:-
lWhen path of sight is partially blocked.
lWhen any of the sensors is subjected to dirt and/ or moisture, smoke accumulating on the lens surface.
lWhen dirt, smoke & moisture is present in the atmosphere between the sensor and target.
The pyrometer temperature measurement method utilizes the fact that objects emit thermal radiation in an
amount that directly corresponds to their own temperature and surface emissivity. Two color pyrometer involves
measuring thermal radiance at two different wavelengths and inferring the temperature from the ratio of these
spectral radiances. Radiance ratio thermometers can be significantly more accurate than single band
thermometers in many applications and hence known to be work in smart mode.
The pyrometer sensor detects the amount of infrared radiation emitted by the measured object (target). The
infrared signal is analyzed and the temperature it represents is analyzed by built-in microprocessor.
üPreheating üMelting
üAnnealing üSintering
üTempering üSoldering
üWelding üRolling
üForging üBrazing
üHardening üNormalizing
üAST pyrometer üManual
üConnection cable 12-core (length - 5 m) üCertificate of calibration
üAST software CD üUSB Grabber Card
Standard Item supplied with AST A250C+ FO PL
The applications in which AST pyrometers can be used are

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2.2 Technical Specifications
Dimensions
Fig. 1 Dimensions of Pyrometers
Model
Temperature Range
(Analog sub-range adjustable)
Spectral Range
Photodetector Type
Distance to Spot Size Ratio
Response Time
Accuracy
Repeatability
Sighting Options
Analog Output
Operating Temp. Range
Storage Temp. Range
Adjustable Parameters and Features via
Software
A250C+ FO PL
350°C - 1000°C
450°C - 1350°C
1.5/1.6 µm
InGaAS/InGaAS
100:1 OH(I)
100:1 OH(lI)
100:1 OH(ll) - Variable
200:1 OH(l)
200:1 OH(ll) -
200:1 OH(ll) - Variable
100 msec adjustable upto 10 sec
± 0.5% of the measured value + 1°C
0.1% of reading in °C + 1°C
Laser Pilot Light(PL)
Digital Output RS-485
0°C…….70°C
Optical Head and Fiber Optic Cable upto 250°C
-20°C…70°C
Emissivity, Response Time, Clear Time (Peak Picker), Analog Output, Analog Scale (Sub range), Unit
Of Temperature(°C/°F), Communication mode (Comm. mode), Record feature, Relay set
point & hysteresis, etc.
0-20mA, 4-20mA (User selectable)
Power Supply
Power Consumption
Laser Power
Protection Class
Housing
Isolation
Operating Humidity
Weight & Dimensions
12V to 28V DC with reverse voltage protection
Max 4.0 watt
<1 m watt (only PL model)
IP65
Stainless Steel
Power supply,Digital output and Analog output are galvanically islolated against each other
10-95%, Non-Condensing Conditions
1200g, Dia= Ø 56mm; Length=188.5mm
Emissivity (ε) 0.1….1.0 adjustable (Single color mode)
Adjustable Parameters and Features via
Keypad
Emissivity, Response Time, Clear Time (Peak Picker), Analog Output, Analog Scale (Sub range), Unit
Of Temperature(°C/°F), Communication mode (Comm. mode), Relay set point & hysteresis, address,
etc.
Relay output One Relay output with hysteresis 60V DC / 42 AC RMS, 0.4 A
Emissivity Slop (ε1/ )ε20.75….1.25 slop adjustable (Two color mode)
350°C - 1000°C
450°C - 1350°C

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Variable Optics
Working Distance (WD) (mm)
Optical Head Length L (mm)
Optical Pullout P (mm)
Optical Head - ll - V (Variable)
250
78.9
12.5
300
75.75
9.35
400
72.8
6.4
600
70.1
3.7
800
68.8
2.4
1000
68.1
1.7
1500
67.15
0.75
2000
66.7
0.3
2500
66.4
0
Spot Size (mm) AST A250C+ FO PL 1.3 1.5 2.0 3.0 4.0 5.0 7.5 10.0 13.0
10
Aperture
4000
66.7
0.3
5000
66.4
0
28.0 38.0
Variable Optics
Working Distance (WD) (mm)
Optical Head Length L (mm)
Optical Pullout P (mm)
Optical Head - lll - V (Variable)
340
158.7
40.0
400
150.3
31.60
600
136.8
18.1
800
131
12.3
1000
127.8
9.1
1500
123.8
5.10
2000
121.9
3.20
Spot Size (mm) AST A250C+ FO PL 0.80 1.0 1.5 2.0 2.5 3.75 5.0
12
Aperture
3000
120
1.30
5000
118.7
0
7.50 12.5
*All Dimensions in mm
2.4 Optics
The pyrometer measure temperature by receiving heat radiation from the object whose temperature has to be
measured. This heat radiation is passed through the lens sensor and then converted to an electrical signal. The
farther the measured object from the pyrometer, the larger the area that will be measured.
Adjusting the required measuring distance:-
To achieve the spot sizes mention in the table above required measuring
distance must be adjusted. This can be done between the smallest and the
biggest limit value. For releasing the optics has to be turned anti clock wise.
Then it can be pushed or pulled to find the correct measuring distance. For
fixing the optics has to be turned clock wise.
Adjusting the measuring distance with the help of the table:-
The table mentions the minimum and maximum measuring distance for each
optics as well as serval other values. The length “L” can we measured with a
caliper. This length "L" can reach max. upto 14 mm.
Adjusting the measuring distance with help of the thru lens view finder:-
The focusable optics is correctly adjusted to the required distance, if the
measuring object is shown as a sharp image in the view finder. A circle marks
the position of the measuring spot.
Adjusting the measuring distance with help of the laser targeting light:-
On the focused measuring distance the laser has a smallest spot size.
length “L”
Unlock
Anticlockwise
Lock
Clockwise
Fig. 2 Adjusting Measuring Distance
Example of OH(ll) - Variable
Pull Out (P) = 1.7 mm
Optical Head Length (L) = 68.1 mm
SS 5.0 mm
L= 68.1
P=1.7 WD 1000 mm
Example of OH(lll) - Variable
SS 2.5 mm
WD 1000 mm
L= 127.8
P=9.1
Pull Out (P) = 9.1 mm
Optical Head Length (L) = 127.8 mm
*All Dimensions in mm
Optical Head
Optical Head - I
Optical Head - II
120
260
700
90
200
600
4500
Working
Distances (mm)
350°C - 1000°C
450°C - 1350°C
1.2
2.6
7
0.5
1
3
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Chapter - 3
Basics & Installation of the Pyrometer
3.1 Infrared temperature measurement of an object
Each and every object emit definite amount of infrared radiation and its intensity varies according to the
temperature of object. Wavelength of infrared radiation lies approximately between 0.7 to 14 µm depending on the
material and properties of object. Infrared radiations are sometimes also referred to as “heat radiations” depends
mostly on the material. This material dependent constant value is known as “emissivity”, have a look at appendix B
for emissivity values.
3.1.1 Emissivity (Ɛ)
Emissivity is the ratio of energy radiated from an object to the exterior and energy radiated from blackbody. The
emissivity varies with the surface condition of the object and also with temperature variation and wavelength. If this
value is not accurate, then the true temperature cannot be measured. In other words a variation or change in
emissivity will cause a change in the measurement.
If the value of emissivity low, your measured results may contain some errors due to interfering infrared radiations
form objects which are behind the target object like heating systems, fireclay brisk etc. Usually such type of problems
occurs while measuring very thin materials like glass, plastic etc or some reflecting surface.
This error can be reduced if the sensor is shielded from reflecting radiation sources and also by properly, carefully
installing the device.
By the application of Kirchhoff's law of thermal radiation “at thermal equilibrium, the emissivity of the body is equal
to its absorptivity (α)”. So for perfect black body, Ɛ is 1 while any real object would have Ɛ less than 1. Also the
transmissivity (т) and reflectivity (ρ) is zero. The sum of absorptivity, reflectivity and transmissivity is always 1.
α + ρ + т = 1
By emissivity factor materials can be categorized as
üMetals
üNon metals
üTransparent materials
3.1.2 Calculation of emissivity of target object
There are various methods to do so but one of most prominently used is Calculate the actual temperature of target
object using a RTD, Thermocouple etc. Measure the object's temperature by pyrometer and adjust emissivity
settings in pyrometer unless correct temperature value is reached. Hence correct emissivity is measured of the
target object.
3.2 Installation
3.2.1 Mechanical installation of pyrometer
After all preparations are completed you can install pyrometer. Installation of pyrometer depends on the type of
bracket you are using and the type of surface.
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3.2.3 Viewing Angles
The pyrometer can be placed at any angle from the target object up to 30°. indicated in the below diagram.
Fig.3 Proper mounting of pyrometer
Fig. 4 Pyrometer Acceptable Viewing angles
Background
Best
critical
Incorrect
Pyrometer
Target greater than
spot size
Target equal to
spot size
Target smaller
than spot size
Acceptable
Angles
Pyrometer
Best
90°C to target
Good
30°C to 90°C target
Bad
0°C to 30°C target
3.2.2 Distance of pyrometer from object
The desired spot size on the target will determine the maximum measurement distance and the focal length of the
optical module. To avoid wrong readings the spot size of target must contain entire field view of the pyrometer. The
pyrometer must be mounted so the entire field of view is the same or smaller than the desired target size. This is
indicated in the below diagram.

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3.3 Location selection
Qualified operating person should do the installation. Location should be good enough so that pyrometer should get
continuous infrared radiation.
Pyrometer distance from object is according to below points:-
1. Pyrometer spot size should be small than object size.(read 3.2.2 & 3.2.3)
2. Know your pyrometer spot size according to point 2.3.
3. Pyrometer ambient temperature should be within 0° to 70°C (read 3.3.3).
3.3.1 Correct Positioning of the pyrometer
With pilot light (PL)
A laser targeting light will help to correct the position of the pyrometer. It is recommended that laser should be
switched off while measurement. It will increase the life of laser. To avoid measuring errors caused by a too big spot
size the pyrometer must be fixed in the correct measuring distance, so that the object under measurement fills the
spot size.
With through the lens sighting (TL)
In case of through the lens sighting a reticule circle marks the position of the measuring spot. This circle is true-sided
and parallax-free.
With composite Video output
In case of video output a reticle circle on the center of camera view marks the positioning of the measuring spot. The
camera view shows real temperature of the target and reticle on the center of the view.
Note: The laser spot (PL) / reticule circle (TL) is only for indication of measuring spot, not exactly shows the measuring
area.
3.3.2 Mounting of pyrometer
To install the pyrometer at the place of measurement a mounting support is supplied as an accessory, after losing the
clamp screws, pyrometer can be mounted correctly in the mounting clamp.
3.3.3 Ambient temperature
The allowed operation temperature for the pyrometer is 0°C to 70°C. Therefore if pyrometer is to be used above
70°C upto 200°C water cooling jacket with built in air purge unit is used otherwise it may damage the pyrometer. The
ambient temperature is dependent on the temperature and flow rate of cooling water. Details of water cooling
jacket& air purge are given in point 3.4.1.
3.3.4 Atmospheric conditions
The pyrometer cannot receive the full infrared energy for the measurement if atmospheric conditions like smoke,
dust or steam are present and hence it result in measuring error. An air purge unit can be helpful to avoid
contamination such as dust and humidity on the lens. The air supplied should be at normal temperature with oil &
moisture free. The air purge generates an air stream shaped like a cone and blows particles from the lens area.