In the pressure sensor maintenance work , through integration of data and found that the sensor problems generally are the following : 1 , base, and a lot of oil around the plate four weeks , thus causing the insulation effect is not ideal. 2 , the gap between the base plate and the other end of the small end large, this is because the sensor base of the following mill base circle , which has been subject to the impact of the role of the rolling force , no longer meet the installation requirements , when the level of the . 3 , after the sensor is removed , the same position that it has the appearance of a very severe wear , some have even been corrosion , so the force is no longer uniform . 4 , the west under the indenter roll the extent of damage severe than the east , the number was significantly higher , analyze the results that may be mill drive west end , so by rolling impact will be higher than the big east .
Respond to some of the problems above we generally there are several solutions. 1, from the rolling mill stand removed at Crankshaft Positioning Sensor base , and then measure the surface and the lower surface of the base circle , the horizontal and flatness must be measured. 2 , the lower plate below the increase in skin thickness of 0.6mm copper because of its good ductility , a level sensor is installed can have a certain compensation. The pressure test data show that the new added to the copper plate at certain positions of the indentation has one millimeter thick , and some of them have almost been pressed to wear , this description is not enough to force uniform . 3 , removeCoolant Temperature Sensor after the sensor , both the upper and lower plate and pad roughness , flatness , parallelism and geometry measurements , generally can be found in both the upper and lower platen plate precision installation requirements have been much lower than the . Only learn how to maintain mill pressure sensors, in order to make better use of rolling pressure sensor , the only way to make life more permanent , better service.
Crank position sensor is usually installed in the distributor, the control system is the most important one of the sensors. Its role is: detecting the engine speed, so-called rotation speed sensor; detects the piston top dead center position, it is also known as the only point sensor, including the detection of each cylinder for controlling the ignition TDC signal for controlling sequential spray oil first cylinder TDC signal
Automotive Temperature Sensors
Automotive Temperature Sensors
2013年10月20日星期日
How to maintain the mill pressure sensor
Whatever the instrument used in a long time, the life expectancy would decline . Mill pressure sensor is no exception. Pressure sensors are very important element , which is detected when the mill rolling force , it is critical components. It is mounted on the roll , and each has one side . On the steel sheet surface by measuring the total pressure force, the detected differential pressure can truly reflect the fact on the steel sheet surface uniformity of the pressure . Because it is mounted under the roll , and the environment in which it has always been very strong vibration , humidity is very high and the temperature is high. Therefore, to maintain it becomes a very difficult thing , but expensive. Therefore, how well and how to maintain the reserve sensor is especially important parts .Crankshaft Positioning Sensor installation has the following technical requirements: the sensor should be installed in the roll head below the base , the above is of ninety millimeters thick are plate , and on top of it is on a 60 mm thick plate , the following part is the next fifteen millimeters thick pad . In fact , over Car Temperature Sensor plate with the following , both the base plate and the distance between the circumference of 1.5 mm. And there is a convex bottom base , which is embedded into the mill base inside . Both upper and lower pads, and the quality of some of the requirements of the platen . Heat treatment Hardness : HB320-360. Surface roughness of 1.6um; flatness 0.05mm; parallel is 0.05 .
Non-contact temperature sensor sensitive components in contact with the measured object and do not
Non-contact temperature sensor sensitive components in contact with the measured object and do not , also known as non- contact Thermometer . This Automotive Temperature Sensors is used to measure moving objects instrumentation , small target and heat capacity smaller or rapid temperature changes ( transient ) the surface temperature of the object , can also be used to measure the temperature of the temperature distribution . The most commonly used non- contact Thermometer Based on the basic law of blackbody radiation , called radiation thermometer tables. Including brightness radiation thermometry method ( see optical pyrometer ) , radiation ( see radiation pyrometer ) and colorimetry ( see colorimetric thermometer ) . Various types of radiation thermometry method can only measure the temperature corresponding to the luminosity , temperature or radiation colorimetric temperature . Only blackbody ( absorbs all radiation is not reflected light of the object ) is the real temperature of the measured temperature . To determine the true temperature of an object , it must be material surface emissivity correction . The emissivity of the material surface depends not only on temperature and wavelength , but also with the surface state , and microstructure of the coating , etc., and therefore difficult to accurately measure . In automated production method often requires the use of radiation to measure the temperature or the surface temperature control some , such as metallurgical rolling temperature of the strip , the roll temperature, the forging temperature, and a variety of molten metal in the smelting furnace or a temperature in the crucible . In these particular cases , surface emissivity measurement is rather difficult . For solid surface temperature automatic measurement and control, the use of additional mirror surface with the composition of the measured blackbody cavity . Additional effects of radiation can increase the effective surface to be measured and the effective radiated emission coefficient . By using effective instrument for emission coefficient measured temperature corrected accordingly , and ultimately obtain the true temperature of the measured surface . The most typical auxiliary reflector is hemispherical reflector . Coolant Temperature Sensor the center of the sphere diffuse radiation reflected back by the mirror surface of the hemispherical form additional radiation, thus increasing the effective emission coefficient of the formula: wherein ε is the emissivity material , ρ is the mirror reflectivity. As to the gas and the liquid medium to the real temperature radiation measurements, the heat-resistant material can be inserted into the tube to a certain depth to form a blackbody cavity approach. Obtained by calculation to reach thermal equilibrium with the medium after the effective emission coefficient cylindrical cavity . In the automatic measurement and control can use this value for the measured temperature at the bottom chamber ( ie, medium temperature ) is corrected to obtain the true temperature of the media .
Contact type temperature sensor and the measured object detecting portion has a good touch , also known as a thermometer
In recent years, the continuous development of science and technology , China's science and technology into the automation, digitization of the new field , which is used to place the temperature sensor a lot more . With the low-temperature technology in the defense engineering , space technology, metallurgy, electronics, food , pharmaceutical and petrochemical sectors and the wide application of superconducting technology research, measuring temperatures below 120K cryogenic thermometers have been developed , such as low temperature gas thermometer , steam pressure thermometer, acoustic thermometer, paramagnetic salt thermometer , quantum thermometer , low thermal resistance and low-temperature thermocouple and so on. Low temperature thermometer temperature sensing element requires small size , high accuracy , repeatability and stability. Porous silica glass using carburizing carburizing sintered glass thermal resistance thermometer is a temperature sensing element , for measuring the range of 1.6 ~ 300K temperature. Conductors of two different materials , such as connected to each other at a certain point , the connection point of heating in their unheated parts of the potential difference occurs . Pressure switch the value of this potential difference is not heated and the temperature of the parts of the measuring point , and the material on the two conductors . This phenomenon can be in a wide temperature range occurs , if the potential difference accurately measure , measure the unheated parts of the ambient temperature , heat spots can accurately know the temperature. Since it must have two conductors of different materials , so called " thermocouple ." Thermocouples made of different materials used in different temperature ranges , they are also different sensitivity . The sensitivity of the thermocouple hot spot temperature is added 1 ℃ , the output variation of the potential difference . For most metal thermocouples supporting material is concerned, this value is about 5 to 40 microvolts / ℃ between . Crankshaft Positioning Sensor has its own advantages and disadvantages , which sensitivity is relatively low, the interference signal susceptible to environmental impact, but also susceptible to temperature drift of the preamplifier , therefore not suitable for measuring small changes in temperature. Since the thermocouple temperature sensor independent of the thickness of the material sensitivity , a very thin material can be made of a temperature sensor . Also due to the production of metal thermocouple material has good ductility , this subtle temperature measuring element has a high response rate, can be measured rapidly changing process . Temperature sensor is a wide variety of the most commonly used variety of Cooling Temperature Sensor as a modern form of the temperature sensor was very small, so it is more widely used in various fields of production practices , but also for our life to provide a myriad of convenience and functionality . There are four main types of temperature sensors : thermocouples , thermistors , resistance temperature detector (RTD) and IC temperature sensor. IC temperature sensor also includes analog and digital outputs of two types. Contact type temperature sensor and the measured object detecting portion has a good touch , also known as a thermometer .
2013年10月17日星期四
Tilt sensor on the railway bridge machine application
Railway bridge is a machine for railway bridge construction on the common construction machinery , railway bridge machine in the railway tracks on the road, will make the beams onto the bridge piers , and its main function is to beams filed after delivery to a fixed position down. Erecting machine work great mechanical strength , and every time you need to run a large number of objects and even large tonnage , erecting machine to be hanging beams through the bridge embankment on the bit , and take line high center of gravity and axle load , with the massive there may be roadbed and line quality is poor, such as the curved section outer rails high enough to cause the body tilt cause side friction is large , if the friction is more serious and may lead to unnoticed after overturning accident , the line will lead to uneven slope erecting machine slippery , making it appear forward phenomenon, coupled with factors such as human and prone to dangerous accidents to predict in advance , using the tilt sensor is a good solution Camshaft Position Sensor is used to specifically measure the tilt Cooling Temperature Sensor is able to measure the tilt angle of the object and bridges , real-time monitoring erecting machine tilt angle , and monitor the data transmitted to the control room, adjusted according to actual situation monitoring personnel working status , to security monitoring. Advantages of high-precision analog and digital Engine Coolant Temperature Sensor output single -axis output selectable multi-range selection, free custom enclosure rating high sensitivity, zero correction 40 ~ +85 ℃ temperature compensation module-level static, lightning protection, overvoltage protection, surge protection .
Summary of metal thermal resistance sensor applications
Thermal resistance meter is a metal thermal resistance typical applications of the sensor . RTD juice flow is based on the physics inside the medium made of heat conduction phenomena . If the temperature T1 of the thermal resistance at temperature T2 into the medium , provided the thermal resistance in contact with the medium surface area A, the thermal resistance of the heat dissipation Q can be expressed in: Q = KA (T1-T2), formula , K is the thermal conductivity , or heat transfer coefficient . Experiments show that , K and medium density , viscosity, average flow rate parameters. When other parameters are constant , K- only medium is proportional to the average velocity . By measuring the thermal resistance of the heat dissipation Q can be measured the average velocity or flow medium . Thermistor sensor has a small size, fast response, high sensitivity , so it is widely used in many fields . Camshaft Position Sensor in industrial applications is very wide, depending on the product model, its scope is also not the same line , specifically the following aspects: Thermistor Temperature : As a thermistor temperature measurement sensors are generally relatively simple structure , the price cheaper . No outside protective layer thermistor can only be applied in a dry place ; sealed thermistor afraid of moisture erosion, can be used in a relatively harsh environment . Since the resistance of the thermistor sensor is large, so the connecting wires and the contact resistance of the resistance can be ignored , so Engine Coolant Temperature Sensor at the temperature up to several kilometers of distance measurement applications, multi-use bridge measurement circuit . The principle can also be used as the use of other temperature measurement and control circuit. Thermistor for temperature compensation of the sensor : ThermistorShaft Position Sensor in a certain range to compensate for certain components humidity . For example, moving coil meter moving coil header by the copper wire around the system . Temperature increases , the resistance increases, causing the temperature errors. And can therefore be of the moving coil circuit will be negative temperature coefficient thermistor manganese copper and then with the resistor in parallel with the series compensation components , in which to offset the error caused by temperature changes . In the transistor circuit , logarithmic amplifier , it is also composed of a thermistor compensation circuit used . Compensation due to temperature drift errors . Thermistor sensor overheat protection: thermal protection of direct indirect protection to protect profits . The small current case, the thermistor sensor can directly load string person , to protect the device to prevent overheating damage , for large current applications , can be used for the relay , transistor circuit protection. In either case, the thermal resistance of the device to be protected are close together , so that heat exchange between the full , the event of overheating , the protective effect of the thermistor . For example , the stator winding of the motor thermistor embedded in the mutant and in series with the relay . When the motor is overloaded, the stator current increases , causing fever . When the temperature is higher than point mutations , the current in the circuit can be within a few tens of milliamperes is mutated to tens of milliamps , the relay, in order to achieve thermal protection. Thermistor sensor for liquid level measurement : NTC thermistor sensor to put some heating current , its surface temperature will be higher than the surrounding air temperature, at which point it 's less resistance . When the liquid and higher than its installation height, it would take away the heat of the liquid , so the temperature drops , the resistance increased. Determine its resistance changes , you can know whether the liquid level is below the set value . Oil level in the tank car Automotive Temperature Sensors is produced using the above principle . Thermistor in the car is also used to measure the oil , the cooling water mixed with other .
Rocket technology sensor applications
Rocket launch is like a dragon is never caught not come, in fact, on the rocket in order to ensure safe flight of astronauts to provide accurate input data , the rocket on the various types of sensors , converters play an important role in sensor in the end what kind of role play it , and today China sensors trading network came to tell you about it. Various types of Automobile Temperature Sensor on the rocket , mostly installed inside the key parts of the rocket , they perceived the arrow on the physical changes responsible for the physical quantity conversion converter to achieve the transmission signal supplied to the control system of the rocket and ground control center as a basis to judge , like a change in both eyes fixed targets for the command center to provide a basis to predict . Speaking of rockets internal sensor , manifold variety. Working principle of a capacitive , resistive , optical type , indicators measured pressure, displacement , strain, physical monitoring the acceleration , position, temperature , noise, vibration , etc. aspects. Wide range of Camshaft Position Sensorin the rocket world, there are several categories is particularly important, it is a direct monitoring data reflect the status of the rocket is safe . Acceleration sensor lifesaving escape criterion for the rocket escape system provides important parameters , when the rocket a serious failure , endangering the safety of astronauts , it will show the acceleration deviation from the design value , the sensor will sense this change the first time , and issued signal initiates escape procedures to help astronauts quickly out of the woods . Using the system with level Automotive Temperature Sensors for measuring the remaining amount of propellant level measurement , real time, continuously , accurately provide information on the remaining amount of liquid propellant , controls the engine adjusting valve or open or closed , monitoring the flow of propellant mixing ratio of the engine keep tank oxidant , the mass ratio of the combustion agent is within the optimal range . Vibration and noise is the rocket invisible killer , though does not seem to explode so violently cruel, but the astronauts of the body is also very large destructive . In order to ensure the rocket during flight vibration and noise generated by the human body can not exceed acceptable levels , improve ride comfort of astronauts , rockets also set up a special monitoring vibration and noise of the sensor. Rumbling avalanche of orange flame , daring and took away all eyes , a small sensor on the huge rocket body seem insignificant , but they are protecting the safety of the astronauts unsung heroes in the thousands of degrees of broiled high stick to their posts , so vacated became an astronaut flying dragon tame car.
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