Before installing an ultrasonic flow meter the most important consideration is the medium to be measured. Raw sewage usually requires a Doppler ultrasonic flow meter whilst distilled or clean water requires a time of flight ultrasonic flow meter. However, what about applications that use a combination of liquids or liquids with small particles? For applications where the media has particles of 100 PPM or more a Doppler ultrasonic flow meter would be the most suitable device to use. For media with particles smaller than 100PPM, such as oil, sea water, or even gray water a time of flight ultrasonic flow meter types are most suitable.
A time of flight ultrasonic flow meter requires a totally full pipe to work. While a typical Doppler ultrasonic flow meter is more suited to a completely full pipe, it is possible under certain conditions to utilise these units on partially full pipes.
Sensor Installation
In an ideal condition a straight length of horizontal pipe that is at least fifteen pipe diameters long is required. This should be free of valves, inflow and outflow diffusers and should be as far away from pumps as possible. When using a time of flight ultrasonic flow meter on an installation that has a pump or T-section, a straight length of up to 50 pipe diameters to obtain an accurate flow reading.
Most ultrasonic flow meter models are unable to measure downward flow in a vertical pipe. The pipe surface must also be clean and free from rust or paint bubbles. Also the ultrasonic flow meter transducers must be clean and have a substantial amount of couplant material to make a good acoustic connection.
For horizontal pipes a time of flight ultrasonic flow meter should have the transducers fitted on the side of the pipe. This will allow more accurate flow readings as generally air bubbles are located on the top of a pipe while sediment falls to the bottom. Doppler transducers are generally installed on the top of the pipe.
A typical time of flight ultrasonic flow meter will have two transducers, one will be specifically for the upstream direction of the flow, while the other for the downstream. If you are unsure if the flow direction, you will normally see a negative flow rate if you have installed these incorrectly. If the transducers are installed correctly and you are still having a problem in obtaining a correct figure from your ultrasonic flow meter, try different sound path settings. This will require you to move your transducers up and down the pipe as the ultrasonic wave is reflected a different number of times on the pipe walls. Generally, the more transit paths, the more accurate your reading. However, the more transit paths can also lead to a weaker signal which can cause setup difficulties; this is why it is recommended that you always start with the simple “V" method.
Take care in setting the exact liquid type, sensor spacing and pipe measurements. If you have incorrectly programmed any of these variables in your ultrasonic flow meter you will get either an incorrect reading, or no flow reading at all.
Once you have taken the time and accomplished your first ultrasonic flow meter installation, future measurements will be much easier.
Wireless Temperature Data Logger
Perhaps the most common application for the use of the data logger in the world today is for temperature logging. The temperature data logger is used in factories, offices, hospitals, museums, road transport, and outdoors for environmental monitoring. Here is an outline of typical temperature data logger applications:
Temperature data logger use in factories
The monitoring and logging of temperature is vital in many manufacturing processes. In the food industry a temperature data logger is often used to ensure that unprocessed food is stored at the correct temperature in cold stores. It is also used in ovens and production lines to ensure the food has been heated to the correct temperature for the required length of time
In the semi conductor industry clean rooms and production processes must be kept at a constant temperature to ensure quality control. Here the temperature data logger is indispensable.
In brick works a temperature data logger is used in the oven through process to ensure that bricks are cured to the correct temperature.
Temperature data logger us in offices
Many companies will position a temperature data logger in main working areas throughout their building to verify that a comfortable temperature is maintained during working hours. Staff will sometimes complain that a room is either too hot, or too cold. A data logger can be used to record the actual temperature so that subjective judgments can be corroborated.
Temperature data logger use in hospitals
Hospitals use many types of data logger for temperature recording. Fridges and freezers where drugs and samples are stored will have a temperature data logger permanently installed. Incubators are also generally monitored for temperature and here a data logger is often used for historical data.
Temperature data logger use in museums and art galleries
In paintings many artefacts are extremely sensitive to temperature. It is common for a temperature data logger to be placed in each room, and often within individual display cases to monitor ambient temperature. In art galleries paintings are very sensitive to temperature. As well as placing a data logger in each room, sometimes a temperature data logger is also fitted within the frame of very old paintings, particularly those painted on wood.
Temperature data logger use in environmental monitoring
In addition to general weather monitoring the temperature data logger is used widely to log temperature over large areas where scientists and researchers need to have exact ground temperature data. Typical examples are glaciers, rain forests, mountain areas, and polar regions. A temperature data logger can also be used to monitor rivers and lakes.
Temperature data logger use in road transport
Sensitive or delicate goods, in particular foodstuffs can often be in transit for many hours or days by road. A data logger can be used to check that goods in refrigerated trucks have been maintained at the correct temperature throughout a journey. In the UK it is now a requirement to use a data logger to record temperature in vehicles used for livestock transportation.
Both Imrozz Duff & Jim Furness are contributors for EditorialToday. The above articles have been edited for relevancy and timeliness. All write-ups, reviews, tips and guides published by EditorialToday.com and its partners or affiliates are for informational purposes only. They should not be used for any legal or any other type of advice. We do not endorse any author, contributor, writer or article posted by our team.
Imrozz Duff has sinced written about articles on various topics from Fishing, Information Technology. Jim Furness is the CEO of Omniinstruments Ltd, specialists in data logger and other instrumentation solutions such as. Imrozz Duff's top article generates over 1300 views. Bookmark Imrozz Duff to your Favourites.
