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Accuracy To Top^
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Q.
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Is it OK to move the sensors to get a better signal? How does this effect accuracy?
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A.
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No. The separation distance is calculated by the instrument depending on the pipe size and temperature, and must not be changed. How it effects the accuracy depends on how much you move the transducer.
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Q.
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As there is no temperature compensation, how does a change in application temp effect the accuracy?
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A.
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+/- 10°C will affect the accuracy by 1%. If the temperature increases a significant amount the signal may be lost altogether. A higher temperature gives a wider separation distance, so if the sensors haven’t moved along with the temperature, then the signal will not be received.
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Q.
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What happens if I get the pipe size wrong?
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A.
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This will affect the volumetric reading. 1mm out on a 50mm pipe is the equivalent to 4% of the overall area, whereas 1mm on a 200mm pipe is only 1%. The instrument measures the flow velocity and then calculates the volumetric reading by the pipe information entered. If this is incorrect the volumetric reading will be incorrect. Use an ultrasonic thickness gauge or pipe tables if a more accurate reading is required.
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Q.
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Is it OK to move the sensors to get a better signal? How does this effect accuracy?
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A.
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No. The separation distance is calculated by the instrument depending on the pipe size and temperature, and must not be changed. How it effects the accuracy depends on how much you move the transducer.
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Q.
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How does the separation distance effect accuracy?
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A.
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The separation distance is calculated, by the pipe material, pipe thickness, temperature and speed of sound of the liquid. If any of this information is incorrect it could affect the accuracy of the unit by a few %. If the separation distance is calculated correctly but set incorrectly, it will have the same effect.
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Q.
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How is accuracy affected by putting the sensors close to a bend?
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A.
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This is really unquantifiable. The readings are calculated assuming the flow is turbulent. What the liquid does when it moves round a bend we cannot contemplate.
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Q.
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Does a low signal effect accuracy?
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A.
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If signal levels go below 25% then the accuracy will be affected.
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Q.
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How do I find the pipe OD?
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A.
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The OD may be stamped onto or sprayed onto the pipe or flange. Where this is not the case a simple tape measure will suffice.
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Q.
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How do I find the wall thickness?
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A.
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If you’re not able to access site design drawings, pipe tables, manufacturer’s part numbers or the same pipework elsewhere on site, the alternative is an ultrasonic thickness gauge which may be hired or purchased through Kimans.
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Q.
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What liquids can be measured?
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A.
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There are two methods of using ultrasound to measure liquid flow, “Transit Time” and “Doppler”. For clean liquids, ie liquids with less than 2% particles or contaminates in, you need to use the “Transit Time” method. For all other applications use the “Doppler” method of measurement.
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Q.
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What liquids cannot be measured?
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A.
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Any liquid that has more than 2% solid content and any that does not conduct ultrasound.
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Q.
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Can I measure Heavy Fuel Oil?
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A.
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This depends on the make up of the oil and the temperature of the application. Kimans would recommend using a portable unit on the application to verify that signals levels before proceeding.
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Q.
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The unit doesn’t read zero?
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A.
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This depends on the make up of the oil and the temperature of the application. Kimans would recommend using a portable unit on the application to verify that signals levels before proceeding.
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Q.
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What are offsets?
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A.
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See above.
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Q.
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How much grease/couplant do I use?
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A.
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On small pipes use only a thin pencil line of grease along the length of each transducer face. On larger pipes with “B” and “C” transducers more couplant may be used. It also needs to be applied along the length of the transducer, and applied as it comes out of the tube.
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Q.
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Can I use the U100 on any other pipe size?
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A.
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The U100 is calibrated for a specific pipe size, depending on the customer’s requirements. If it needs to be used on other applications it will need to come back to Kimans to be re-calibrated.
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Q.
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What pipe materials do the instruments work on?
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A.
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Any sonic conducting medium such as Carbon Steel, Stainless Steel, Copper, UPVC, PVDF, Concrete, Galvanised Steel, Mild Steel, Glass, Brass. Including Lined Pipes – Epoxy, Rubber, Steel, Plastic.
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Q.
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Does the unit work on concrete lined pipes?
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A.
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Although Kimans have sold units into applications that use concrete lined pipes, we have found some types of concrete pipe can be difficult to get ultrasound through. We would therefore recommend a site survey before going ahead with a purchase.
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Q.
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Does the unit work on galvanized pipe?
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A.
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Any sonic conducting medium such as Carbon Steel, Stainless Steel, Copper, UPVC, PVDF, Concrete, Galvanised Steel, Mild Steel, Glass, Brass. Including Lined Pipes – Epoxy, Rubber, Steel, Plastic.
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Q.
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Does the unit work with Flexible hose?
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A.
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No. The unit only works on rigid pipework.
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Q.
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What happens if the temperature of the application goes above the maximum specified?
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A.
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If you still get a reasonable signal then the readings should be fine for short periods of time. If the temperature goes above the specified temperature for long periods of time you could end up damaging the transducer.
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Q.
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My unit is reading negative flow?
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A.
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Make sure the flow is going in the right direction. The instrument will read positive again if the cables are reversed. Read the manual to make sure the correct cable is up stream.
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Q.
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What are the Flow rates for these meters?
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A.
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Refer to the manual supplied with the unit for maximum flow rates, to see what the unit is capable of. This varies depending on the pipe size and the sensors that are used. All units read higher velocity on small pipes, which reduces as the pipes get larger.
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Q.
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Why does the max flow rate reduce when the pipe size increases?
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A.
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Kimans use a phase detection system that limits maximum velocity we can measure. Changing the sensors from reflex to diagonal mode will double the velocity range of the instrument. We also have a range of high velocity sensors for double the velocity again.
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Q.
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I have negative separation distance, how is this possible and how do I fix it?
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A.
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This is obviously not practical. It may be possible to force the unit into double or triple bounce to increase the separation distance.
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Q.
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I seem to be getting lower flow readings with Stainless steel pipes?
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A.
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It may be that noise or wall signals affecting the reading. Try using the unit in either double or triple bounce to alleviate the problem.
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Q.
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If I need to use a liquid other than water how does this change things?
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A.
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Select from the list of liquids programmed into the unit. If the liquid you are measuring is not in the list, us the tables at the back of the manual for the correct speed of sound for your particular application.
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Q.
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What effect does extending the sensor cables have?
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A.
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The sensors are supplied as matched pairs. As long as the cable are the same length anything up to 50 metres in length will not be a problem.
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Q.
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If I need to use a liquid other than water how does this change things?
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A.
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Select from the list of liquids programmed into the unit. If the liquid you are measuring is not in the list, us the tables at the back of the manual for the correct speed of sound for your particular application.
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Q.
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If I need to use a liquid other than water how does this change things?
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A.
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Select from the list of liquids programmed into the unit. If the liquid you are measuring is not in the list, us the tables at the back of the manual for the correct speed of sound for your particular application.
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Q.
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If I need to use a liquid other than water how does this change things?
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A.
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Select from the list of liquids programmed into the unit. If the liquid you are measuring is not in the list, us the tables at the back of the manual for the correct speed of sound for your particular application.
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Q.
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Unit doesn’t switch on?
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A.
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Check power supply – use a multimeter to make sure this is working? Is the battery charged? Is the charger working?
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Q.
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How long do the batteries last?
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A.
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Anywhere between 4-36 hours depending on the instrument.
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Q.
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How long does it take to charge?
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A.
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This also depends on the instrument; please refer to the manual supplied with the unit.
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Q.
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Can I use the unit with an external battery?
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A.
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Kimans supply a 9-12volt converter, to enable the user to connect the units to an external battery (e.g. car battery).
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Q.
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How can I dispose of the battery?
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A.
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Disposal requirements for batteries can vary from country to country. Please contact your local government for disposal or recycling practices in your area.
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Q.
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Can I remove the battery from the unit to charge it up?
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A.
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No. The battery needs to stay connected in the unit to be charged.
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Q.
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If I need to use a liquid other than water how does this change things?
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A.
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Select from the list of liquids programmed into the unit. If the liquid you are measuring is not in the list, us the tables at the back of the manual for the correct speed of sound for your particular application.
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Q.
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How often does the unit need to come back for calibration?
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A.
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Portable units have a 12 month calibration certificate and should be returned to Kimans each year.
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Q.
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Do I need to return the sensor set with the instrument in order for it to be calibrated?
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A.
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Kimans requires the set of sensors that were provided with the instrument and that are to be used with the instrument for accurate calibration to be carried out.
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Q.
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Which flowmeters have dataloggers?
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A.
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Portaflow SE and 300 models only. Other units can connect either the 4-20mA or pulse outputs to an external data logger.
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Q.
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What is Hyperterminal?
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A.
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Hyperterminal is a piece of software that is provided with most Microsoft operating systems. It enables the user to download data from a variety of data logging equipment including some Micronics equipment. It can be found by going to the start menu, programs, accessories, communications.
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Q.
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How do I download data from my Portaflow 300/SE?
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A.
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This procedure is explained in the instruction manual.
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Q.
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What is the memory size in the Portaflow 300/SE? How much data will be stored?
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A.
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The data logger in the PF300 and PFSE has a 50000 point memory size. One set of information – date, time, flow, units equates to one data point.
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Q.
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How many different locations can I record?
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A.
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Data is recorded in blocks. When a new site or readings are recorded it will start from the next available block of memory. There are over 200 blocks that can be used.
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Q.
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How long will the logger last?
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A.
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The more frequent readings are taken the sooner the memory will be filled. If the logger is set to record a reading every 1 hour, this equates to approximately 2000 days. If the logger is set to record every 3 seconds it will last just under 2 days.
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Q.
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I’m having problem downloading data? What am I doing wrong?
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A.
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Check that the RS232 cable is not faulty and plugged in, follow the procedures in the relevant manual for your device.
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Q.
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My battery has just run out, will I lose all the data and how do I get it back?
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A.
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The logger data remains written to the memory of the unit even if the battery runs out, follow the normal procedure for powering up and recharging the appliance. When you next switch the instrument on, the data should be in memory.
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Q.
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Can I use several sensors with one set of electronics?
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A.
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No.
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Q.
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How much grease or couplant do I use on each transducer?
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A.
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On small pipes use only a thin pencil line of grease along the length of each transducer face. On larger pipes with “B” and “C” transducers more couplant may be used. It also needs to be applied along the length of the transducer, and applied as it comes out of the tube.
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Q.
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Can I use the sensors on vertical and horizontal pipes?
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A.
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Transducers can be mounted on both vertical and horizontal applications. On horizontal pipes make sure the sensors are NOT fitted to the top or bottom of the pipe, where there is a likelihood of air or sediment affecting the signal levels.
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Q.
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What service do Kimans offer?
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A.
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Kimans can carry out installation and commissioning works in the most M.E. countries. Generally however, the customer will install the unit and Kimans will commission it.
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Q.
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If the customer installs the UF2000 unit what is expected?
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A.
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The instrument transmitter unit should be mounted on the wall at a convenient place where a reading can be read off the display – depending how accessible or easy to tamper you want the unit to be. This should have been considered at the time of purchase.
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Q.
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What considerations do I need for mounting the Ultraflo 2000 transmitter?
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A.
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- Convenience - The transmitter unit should be mounted on a wall at a place where a reading can be read off the display by site personnel, caretakers etc.
- Access to view display - The instrument displays flow rate and total or heat flow and total for the most part so this should be accessible to view.
- Access to change / view settings – the unit is password protected and the display door is covered by a hinged door which may be screwed down which offers some deterrent to tampering. Settings may be changed / viewed, units changed or the totaliser reset. Sufficient access should be made for approved personnel.
- Normal considerations for mounting a mains powered device from a health and safety point of view as well as electrical safety.
- Connection of cables for mains supply, sensor cables, connection of output, cables to a control system, BMS or BEMS as well as PT100 probes in the case of the heatmeter.
- Cable conduit and trunking with corresponding cable lengths through such trunking. Kimans are able to supply the sensor and PT100 cables in 3m, 5m and 10m cables as standard and longer lengths as needed. All other cables are provided by the customer.
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Q.
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What considerations do I need for mounting the Ultraflo 2000 sensors?
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A.
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10-15 pipe diameters up and downstream of flow sensors - see manual for further info.
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Q.
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What considerations do I need for mounting the Ultraflo 2000 heatmeter PT100 probes?
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A.
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Ensure that the hot PT100 sensor is placed on the flow line, at the hottest expected point in the application. The PT100 cold sensor should be placed on the return line, at the coldest expected point.
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Q.
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What type of pulse outputs do the units give? What output/voltage?
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A.
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The pulses are from a mechanical relay, maximum 1 pulse per second, 0-5V and are not frequency pulses.
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Q.
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Is the 4-20mA output loop powered? Will it drive another system?
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A.
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No. The line will need to be powered by other means.
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Q.
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What is the max impedance/load you can put on the 4-20mA output?
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A.
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The 4-20mA chip is driven by 15V. Therefore the max load you can have on the circuit at 20mA is 750V. If the error or fault condition output is set to 22mA then the impedance is 680V.
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Q.
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What does the pulse output do when the flow reverses?
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A.
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It stops working. The pulse only works when the flow is forward.
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Q.
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What output signal can we have if the flow reverses?
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A.
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The 4-20mA can be set to for the maximum negative flow and the maximum positive flow, so when the flow is zero the output should be 12mA.
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Q.
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The processor is corrupted and the unit needs to be re set.
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A.
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This process is the same for the PFSE and the PF300
From the main menu, scroll to setup instrument and press enter.
Now scroll to factory settings and press enter.
You will need to input this password with the following buttons:-
Scroll up, 6, 5, scroll down, 7, 4, 2, 1.
Note the scroll buttons may double bounce so you have to give them a very quick push if you see what i mean otherwise you will have to start again.
Now scroll to the zap function and press enter. The unit will now be zapped. Press enter again.
Now exit and switch the unit off and back on again and re-enter all your pipe data.
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Q.
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No signal/Poor signal? What do I do?
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A.
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1. Check the sensors by listening to block they should be making a buzzing sound.
2. Check the sensors are on the pipe/in the guide rail the correct way. The crystals are in the sensor block at an angle. If they are pointing away from each other you will not receive a signal.
3. Is it possible to stop the flow? The will allow any entrained air or particles to settle out, and should improve your signal. If this happens the application is the problem and not the instrument.
Is there sufficient grease? When was grease last applied?
Try diagonal mode to improve signal?
Make sure the sensors are on the side of horizontal pipes and not on the top.
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Q.
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What is a poor signal and what effect does this have on the accuracy/reading?
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A.
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Signals below 30% are low and may affect the readings. Signals below this level will also not record TOTAL values.
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Q.
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My unit is displaying an error message what does it mean?
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A.
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1.The sensors may be positioned too near to an obstruction or bend causing turbulence, or the instrument is being used outside its normal flow range.
2. The sensors may not be able to send or receive signals, check all cable s are connected, transducers are on the pipe correctly with grease on the face.
3. The pipe may be partially empty, aerated or have a high particulate content.
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Q.
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I’m getting the Error message “High flow” but the signal is showing 50%?
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A.
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This can be associated with velocities that are higher than can be measured by the instrument, excessive turbulence or entrained air in the system.
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Q.
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Can the application be altered to modify pipework and allow for an ‘always flooded section’ of pipe?
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A.
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Yes, as long as the pipe stays full. U bends are possible but if it is not long enough it could affect accuracy.
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Q.
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What liquids can be measured?
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A.
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Transit time meters can measure most liquids as long as they are free from entrained air and solids.
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Q.
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What liquids cannot be measured?
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A.
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It is not possible to measure Hydrofluoric acid or Polyurethane
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Area Velocity Flow Theory To Top^
The ultrasonic sensor is installed at the bottom of a pipe or channel. To measure water level the sensor transmits ultrasonic pulses that travel through the water and reflect off the liquid surface. The instrument precisely measures the time it takes for echoes to return to the sensor. Based on the speed of sound in water, the level is measured with accuracy of ±0.25%. Flow velocity is measured with an ultrasonic Doppler signal continuously injected into the water. This high frequency sound (640 KHz) is reflected back to the sensor from particles or bubbles suspended in the liquid. If the fluid is in motion, the echoes return at an altered frequency proportionate to flow velocity. With this technique the instrument measures flow velocity with accuracy of ±2%.
Area-Velocity Flow Meters work in partially full and surcharged pipes, rectangular, trapezoid and egg-shaped channels.
A separate down-looking ultrasonic sensor can be used for highly aerated or turbulent flow applications. It measures level by transmitting ultrasonic pulses through the air to the liquid surface with accuracy of ±0.25%. Along with the level sensor, a submerged Doppler velocity sensor is used to measure the water velocity.
Doppler flow meters measure flow from outside a pipe with a strap-on sensor. Greyline Doppler meters continuously transmit high frequency sound (640 kHz) that travels through the pipe wall and into the flowing liquid. Sound is reflected back to the sensor from solids or bubbles in the fluid. If the fluid is in motion, the echoes return at an altered frequency proportionate to flow velocity. Doppler flow meters continuously measure this frequency shift to calculate flow.
The Doppler effect was first documented in 1842 by Christian Doppler, an Austrian physicist. We hear everyday examples of Doppler: the sound of a train whistle changing pitch as it passes by, or the exhaust noise from a race car as it speeds past our location.
The Doppler technique only works on liquids which contain solids or gas bubbles to reflect its signal. These are "difficult" liquids that may damage regular flow meters: slurries, sludge, wastewater, abrasives, viscous and corrosive chemicals. Because the sensor mounts on the outside of the pipe, there is no pressure drop and no obstruction to flow.
For best performance Doppler sensors should be mounted away from turbulence creating devices like pipe elbows and tees, and away from velocity increasing devices like controlling valves and pumps. Typical accuracy is ±2% of full scale.
Doppler instruments include a strap-on sensor, connecting cable and an electronics enclosure which can be mounted at a convenient location nearby (within 500 ft / 152 m). Sensors can be rated intrinsically safe for mounting in hazardous-rated locations.
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