Hello friends welcome back to my channel calibration Academy if you are new to this Channel and if you have missed our most recent previous videos you can find a link in the description box to watch this video and if you have not subscribed to our Channel yet then please subscribe to our Channel and press the Bell icon to get notifications when we post a video on the channel my today's video is on radar level measurement in the first part of this video you will learn the working principle of the radar level transmitter you will also learn about different types of radar level transmitters lastly you will learn about mounting guidelines of radar level transmitters so please watch this video till the end radar level transmitter works on time of flight measuring principle or time domain reflectometry principle in radar level measurement transmitter sends high frequency radar pulse that traveling at the speed of light towards the bottom of the tank and these pulses bounces of the product surface and return to the sensor then the transmitters microprocessor measures the time delay between the transmitted and received Echo signal and calculates the distance to the liquid surface using following formula distance is equal to speed of the light multiply with time delay divided by 2. radar level measurement also depends on dielectric constant of a product as it has direct impact on quality of reflections for example products with high dielectric constant values will reflect strong and clear pulses and these products are excellent for level measurement on the flip side products with low dielectric constant values will absorb more of the pulse and reflecting less pulses so radar level instrument does not give accurate level measurement for these products now let's learn about different types of radar level instruments there are mainly two types of radar level instruments first is non-contact type radar level instrument and second type is guided wave radar instrument non-contact radar level measurement can be done by using two different techniques first technique is pulse radar technique which we have already discussed in first part of video and second technique is frequency modulated continuous wave radar technique in this technique transmitter transmits microwave toward the product surface and the transmitted signal is of continuously varying frequency so when the signal traveled down to the liquid surface and bounce back to the antenna it is mixed with a signal that is being transmitted at that time and the difference in frequency between the received and transmitted signal is directly proportional to the distance to the liquid other type is guided wave radar level measurement this is revolutionary method of liquid level measurement and it works on the principle of time domain reflectometry which is also known as TDR method in TD or method a pulse is transmitted to the measurement vessel using a cable or rod and the pulse signals reflected by the medium surface and received by the processing Electronics the distance of the reflecting object or Surface can be easily calculated by measuring the time difference between the transmitted pulse and the arrival of the first reflection Echo and knowing the speed of light this is a simple and easy to understand principle of guided wave radar level transmitter first of all let's learn the basic operating principle of guided wave radar technology guided wave radar technology is based upon the principle of time domain reflectometry which is an electrical measurement technique that has been used for several decades in various industrial measurement applications in time domain reflectometry method a low energy electromagnetic pulse is guided along a probe and when the pulse reaches the surface of the medium being measured the pulse energy is reflected up the probe to the circuitry which then calculates the fluid level from the time difference between the pulse scent and the pulse reflected and the transmitter can output the analyzed level as a continuous measurement reading through its analog output RS 485 Communications output or optional switching output depending on output options required guided wave radar technology also has the ability to measure a liquid interface a liquid interface is the ability to detect the top liquid level of the media as well as the interface level or level of the media that is below the liquid level which contains a different dielectric property or physical property than the top liquid level being measured a typical application would be an oil and water interface in which the oil being of a lighter specific gravity and lower dielectric than water so oil would be measured as the top liquid level and the water would be the interface level now let's learn some of the advantages of guided wave radar technology guided wave radar level transmitters are able to accurately measure both liquid and solid media and changes in viscosity density or acidity does not affect its accuracy in addition to this this technology is not affected by agitated surfaces such as boiling liquid dust foam or vapor furthermore guided wave radar technology has extreme operating capabilities and performs well under extreme temperature and it is capable of withstanding pressures up to 580 PSIG last but not the least guided wave radar level transmitter performs well in difficult applications such as fine powders and sticky fluids some applications that GW are commonly used in is paint latex animal fat soybean oil sawdust carbon black titanium tetrachloride salt and grain to name a few in this section I'm going to explain how non-contact type radar level transmitter works non-contact type radar level transmitter works on time of flight measuring principle or time domain reflectometry principle this type of transmitter sends high frequency radar pulse that traveling at the speed of light towards the bottom of the tank and bounces of the product surface and return to the sensor and the transmitter's microprocessor measures the time delay between the transmitted and received Echo signal and calculates the distance to the liquid surface using following formula distance is equal to speed of light multiply with time delay divided by 2. radar level measurement is highly dependent on dielectric constant of a liquid as it has direct impact on quality of reflections in fact liquids with high dielectric constant values will reflect strong and clear pulses on the flip side liquids with low dielectric constant values will absorb more of the pulse reflecting Less in reducing accurate reading non-contact radar level transmitters typical applications include corrosive or non-corrosive liquid level monitoring sanitary environments caustics small tank or process vessel silos and tote tanks now here are the few of the advantages of non-contact radar level measurement firstly pulse radar transmitters are able to accurately measure both liquid and solid media and they are very cost efficient and easy to use and secondly since the probe doesn't need to come in contact with the media it is great for Industries such as food and beverages medical chemical and petrochemical and oil and gas Industries now in last part of this video I will do comparison of both technology to get clear understandings firstly guided wave radar technology use high frequency radar impulses for level measurement on the other side non-contact radar level technology use microwave pulses for level measurement secondly guided wave radar is contact type level measurement technique on the other side pulse radar is non-contact level measurement technique in addition to this guided wave radar level measurement does not affect by extreme temperature and pressure on the other side airspace determines measurement accuracy of pulse radar level measurement and it is not ideal for extremely difficult applications fourth point is guided wave radar is mounted on the top of the tank and it is not ideal if there is a mixer or other obstacles in the tank on the other side pulse radar is also mounted on the top of tank and it is also not ideal if there is a mixer or other obstacles in the tank on the price perspective guided wave radar is moderately priced however pulse radar is very cost effective and last but not the least performance perspective guided wave is exceptional and performs well and independent of process conditions on the other side pulse radar Technologies performance depends on strength of Reflections and surface conditions first of all let's learn what are the recommended guidelines to install radar level transmitter as you can see for Optimal Performance of radar level transmitter the transmitter should be installed in locations with clear and unobstructed view of product surface secondly do not Mount the transmitter in the center of the tank in addition to this do not Mount the transmitter close to or above the inlet stream ideally transmitter should be installed at other side of the inlet stream and the minimum distance to tank wall should be 8 inch or 200 millimeters lastly the transmitter should be installed with as few internal structure as possible within the signal beam please refer this table for beam angle as you can see from the table different antenna has different beam angle now let's learn what are the key advantages of radar level transmitter radar level transmitter can be used with any types of liquids sludges slurries and some solids this device does not require any compensation for changes in density dielectric or conductivity of the fluid change in pressure change in temperature and most vapor space conditions does not have any impact on the accuracy of level measurements radar level transmitter does not have any moving parts so it has very low maintenance since it is not in contact with measured media it is also good for corrosive and dirty application radar level transmitter has few limitations as well for example as we know it is non-contacting level measurement so good installation is the key to get for accurate level reading the sensor needs a clear view of the surface with smooth unobstructed unrestricted mounting nozzle secondly strengthening bars agitator and pipes can cause false echoes however most sophisticated transmitter have software algorithms to allow masking or ignoring of these echoes and lastly accuracy of this device does effect by load dielectric process fluids because for low dielectric process fluid much of the radiated energy is lost to the fluid leaving very little energy to be reflected back to the sensor thank you friends for watching this video I hope you like this video and if you think our content is informative for you and others then please like and share this video with your friends