FIELD OF THE INVENTION
The present invention relates to a simulator cum calibrator device for calibration of
Molten Steel Temperature measurement system in good order. More particularly, the
present invention relates to a low cost simulator cum calibrator involving simple IC
based mV injector circuit to ensure precise and reliable measurement of Molten Steel
Temperature at Bath of Converters, Ladles at LF etc. and Tundish at CCP, as and
when required by Operation/Instrumentation people in a user friendly manner, the
device is simple in construction, small and compact, easy to handle and carry and
consumes less battery as compared to conventional microprocessor based simulator
cum calibrator.
BACKGROUND ART
Molten Steel Temperature Simulator cum Calibrator is very essential Tool. The
Simulator cum Calibrator is required in every shift for maintenance of Molten Steel
Temperature measurement System required for measurement of Molten Steel
Temperature at Bath of Converters, Ladles at LF etc. and Tundish at CCP. In every
shift this simulator is used for simulation to find out the healthiness of total
Temperature Measurement Systems at BOF, LF & CCP as well as for calibration
checking as and when required by Operation/ Instrumentation people.
In the existing practice, Microprocessor based Simulator imported from abroad is in
use for simulation cum calibration jobs in BOF, CCP & LF, cost of each being 1.36
Lakhs. Repairing of this is not possible due to use of SMD, proprietary type ICs, &
software. Moreover, the foreign manufacturer also discontinued/ phased out earlier
product leading to unavailability of spares and maintenance support. The
microprocessor based units were large in size, more in weight and inconvenient for
the operation/maintenance people to carry at site/plant.
The requirement of an effective and efficient simulator cum calibrator for
temperature measurement systems employed in steel manufacturing is extremely
important because malfunctioning of the Temperature measuring System for any
reason may result in:
(i) Improper ladle Temperature for LF means sequence loss/low
strand availability due to nozzle choking or Break out;
(ii) Converter Through ;
(iii) Converter holding means more Tap to Tap time;
There has been thus a need in the art to providing a low cost, user friendly, yet
reliable simulator cum calibrator device to be used for simulation to find out the
healthiness of total Temperature Measurement Systems at BOF, LF & CCP as well as
for calibration checking as and when required by Operation/ Instrumentation people
to ensure reliable measurement of Molten Steel Temperature at Bath of Converters,
Ladles at LF etc. and Tundish at CCP.
OBJECTS OF THE INVENTION
The basic object of the present invention is directed to providing a low cost, low
power consuming and reliable simulator cum calibrator device to be used for
simulation of Temperature Measurement Systems Molten Steel Temperature at Bath
of Converters, Ladles at LF etc. and Tundish at CCP as well as for calibration
checking as and when required by Operation/ Instrumentation people.
Another object of the present invention is directed to providing a simulator cum
calibrator device to be used for simulation of Temperature Measurement Systems at
BOF, LF & CCP in steel plant which would be easy to maintain/repair with easily
available indigenous spares.
A still further object of the present invention is directed to providing a simulator cum
calibrator device to be used for simulation of Temperature Measurement Systems at
BOF, LF & CCP in steel plant which would have longer operating life and less battery
consumption.
A still further object of the present invention is directed to providing a simulator cum
calibrator device to be used for simulation of Temperature Measurement Systems at
BOF, LF & CCP in steel plant which would be small, compact and easy to carry by
operation/ instrumentation persons at site.
A still further object of the present invention is directed to providing a simulator cum
calibrator device to be used for simulation of Temperature Measurement Systems at
BOF, LF & CCP in steel plant which would involve simple IC based control circuit
without requiring SMD, proprietary type ICs, & software as in conventional
microprocessor based device.
A still further object of the present invention is directed to providing a simulator cum
calibrator device to be used for simulation of Temperature Measurement Systems at
BOF, LF & CCP in steel plant which would serve reliably as a low cost substitute of
expensive imported calibrator.
SUMMARY OF THE INVENTION
The basic aspect of the present invention is thus directed to a low cost calibrator cum
simulator having an injector comprising :
A main circuitry adapted for generating fixed mV; and
A compensating circuitry adapted for generating variable µV based on ambient
temperatures.
A further aspect of the present invention is directed a low cost calibrator cum
simulator wherein said main circuitry producing the fixed mV comprises battery
power source operatively connected to an integrated circuit and further onto fixed
and variable resistances to generate the said fixed mV output and said compensating
circuitry comprises batter power source , operating integrated circuitry and fixed and
variable resistances adapted to generate the variable µV output based on ambient
temperature.
A still further aspect of the present invention is directed a low cost calibrator cum
simulator wherein said variable resistance in said main circuitry is adapted to adjust
the fixed mV output and said variable resistance in said compensatory circuit is
adapted to adjust the type of compensation desired.
A still further aspect of the present invention is directed a low cost calibrator cum
simulator wherein the injector compensated output (VE-VF) =fixed mV output (VA-
VB)- variable output at different ambient temperature (VC-VD).
A still further aspect of the present invention is directed a low cost calibrator cum
simulator wherein said main circuitry and said compensating circuitry are provided as
illustrated in accompanying Figure 1.
The objects and advantages of the present invention is described in greater details
with reference to the accompanying non limiting illustrative figure.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURE
Figure 1: is the circuit diagram of the injector of simulator cum calibrator device
according to the invention involving the main circuit and the compensation circuit.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING FIGURE
The present invention is directed to providing a low cost, low power consuming, user
friendly yet long lasting and reliable simulator cum calibrator device to be used for
simulation of Temperature Measurement Systems Molten Steel Temperature at Bath
of Converters, Ladles at LF etc. and Tundish at CCP as well as for calibration
checking as and when required by Operation/ Instrumentation people.
Previous simulator was microprocessor based, repairing of which was not possible
due to use of SMD, proprietary type ICs, & software. Moreover, battery consumption
of this was so high that four number 9 V battery voltage got down within one and
half month and in this period since injected mV got down, less injected temperature
is displayed which creates confusion about the calibration of the temperature
measuring system.
The injector of the simulator cum calibrator device according to the present invention
is comprises two number IC which are easily available in local market. Moreover
battery life of two batteries are near about one year and even after getting down the
battery voltage below 9V, the injected mV is not changed, hence no confusion arises
about calibration and precise temperature measurement of molten steel bath is
ensured. The present simulator cum calibrator device is compact, small and can be
easily carried in pocket by operator/instrumentation personnel.
Accompanying Figure 1 illustrates the injector circuit diagram of the simulator cum
calibrator device according to the present invention which comprises tow portions:
(a) Block I: comprising main circuit which is producing fixed mV; and
(b) Block II: comprising compensating circuit which is producing µV which varies
with ambient temperature.
It is clearly evident from the above injector circuit that main circuit of block I contain
a IC connected to 9V battery through on/off switch and is connected to a fixed
resistance Rl and a variable resistance R2 in series such that between the terminals
A & B across Rl a fixed mV output is obtained. The compensation circuit of Block II
contains another IC receiving supply from a separate 9V battery and also connected
to a fixed resistance R3 and a variable resistance R4 in series such that a variable uV
output is obtained across R3 between the terminals C & D. the final compensated
output is obtained between the output terminals E & F. Here, the fixed mV output
can be adjusted by R2 and the type of compensation can be adjusted by R4 i.e. S
type, R type or K type etc.
The working of the injector for S type compensation according to an embodiment of
the present invention is illustrated as follows:
For 1650° C, mV injector output is VE - VF = 17.162 mV at ambient temperature 25°
C (17.366 mV - 0.204 mV).
Now in this circuit Block 1 creates fixed mV output VA - VB = 17.312 mV
Block 2 creates variable output at different ambient temperature and at 25°C output
VC - VD = 150 µ V=0.150 mV
So injector output is VE - VF = (VA - VB) - (VC - VD) = 17.312 mV - 0.150 mV =
17.162 mV
Now (VC - VD) will rise 6.4 u V with the rise of 1°C and hence (VE - VF) will
decrease 6.4 µ V with the rise of 1°C
It is thus possible by way of the present invention to providing a simulator cum
calibrator device for simulation of Temperature Measurement Systems Molten Steel
Temperature at Bath of Converters, Ladles at LF etc. and Tundish at CCP as well as
for calibration checking as and when required by Operation/ Instrumentation people,
which is low cost, easy to carry yet capable of ensuring precise and reliable
temperature measurement in user friendly manner and with longer service life free
of maintenance.
We Claim:
1. A low cost calibrator cum simulator having an injector comprising :
A main circuitry adapted for generating fixed mV; and
A compensating circuitry adapted for generating variable jiV based on ambient
temperatures.
2. A low cost calibrator cum simulator as claimed in claim 1 wherein said main
circuitry producing the fixed mV comprises batter power source operatively
connected to an integrated circuit and further onto fixed and variable
resistances to generate the said fixed mV output and said compensating
circuitry comprises batter power source , operating integrated circuitry and
fixed and variable resistances adapted to generate the variable ^V output
based on ambient temperature.
3. A low cost calibrator cum simulator as claimed in anyone of claims 1 or 2
wherein said variable resistance in said main circuitry is adapted to adjust the
fixed mV output and said variable resistance in said compensatory circuit is
adapted to adjust the type of compensation desired.
4. A low cost calibrator cum simulator as claimed in anyone of claims 1 to 3
wherein the injector compensated output (VE-VF) =fixed mV output (vA-VB)-
variable output at different ambient temperature (VC-VD).
5. A low cost calibrator cum simulator as claimed in anyone of claims 1 to 4
wherein said main circuitry and said compensating circuitry are provided as
illustrated in accompanying Figure 1.
6. A low cost calibrator cum simulator substantially as hereindescribed and
illustrated with reference to the accompanying figures.

A low cost simulator cum calibrator device for calibration of Molten Steel
Temperature measurement system in good order is disclosed. More particularly, the
present invention relates to a low cost simulator cum calibrator involving simple IC
based mV injector circuit comprising a main circuit and a compensation circuit
capable of providing compensated voltage output corresponding to a injected
temperature to ensure precise and reliable measurement of Molten Steel
Temperature at Bath of Converters, Ladles at LF etc. and Tundish at CCP, as and
when required by Operation/Instrumentation people in a user friendly manner. The
device is simple in construction, small and compact, easy to handle and carry and
consumes less battery power as compared to conventional microprocessor based
simulator cum calibrator.