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Flow Meter FAQs


Quick Jump (please click the Flow Meter FAQ category to jump to the relevant section)

Application Queries
Application Notes
Battery and Power
Datalogging and Download
Guiderail and Sensor Issues
Installation and Commissioning
Signal Problems
Transit Time Products

Products (please click the Flow Meter product name to jump to the relevant section)

LIT 25

Flow Meter FAQs – Accuracy

Q. Is it OK to move the sensors to get a better signal? How does this effect accuracy?
A. No. The separation distance is calculated by the instrument depending on the pipe size and temperature, and must not be changed. How it affects the accuracy depends on how much you move the transducer.

Q. As there is no temperature compensation, how does a change in application temp effect the accuracy?
A. +/- 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.

Q. What happens if I get the pipe size wrong?
A. 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.

Q. How is accuracy affected by putting the sensors close to a bend?
A. 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.

Q. Does a low signal effect accuracy?
A. If signal levels go below 25% then the accuracy will be affected.

Flow Meter FAQs – Application Queries

Q. How do I find the pipe OD?
A. 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.

Q. How do I find the wall thickness?
A. 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 Micronics.

Q. What liquids can be measured?
A. 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.

Q. What liquids cannot be measured? 
A. Any liquid that has more than 2% solid content and any that does not conduct ultrasound.

Q. Can I measure Heavy Fuel Oil?
A. This depends on the composition of the oil and the temperature of the application. Micronics would recommend using a portable unit on the application to verify that signals levels before proceeding.

Q. The unit doesn’t read zero?
A. This depends on the composition of the oil and the temperature of the application. Micronics would recommend using a portable unit on the application to verify that signals levels before proceeding.

Q. What are offsets?
A. See above.

Flow Meter FAQs – Application Notes

Q. How much grease/couplant do I use?
A. 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.

Q. Can I use the U1000 on any other pipe size?
A. The U1000 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 Micronics to be re-calibrated.

Q. What pipe materials do the instruments work on?
A. 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.

Q. Does the unit work on concrete lined pipes?
A. Although Micronics 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.

Q. Does the unit work on galvanized pipe?
A. 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.

Q. Does the unit work with Flexible hose?
A. No. The unit only works on rigid pipework.

Q. What happens if the temperature of the application goes above the maximum specified?
A. 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.

Q. My unit is reading negative flow?
A. 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.

Q. What are the Flow rates for these meters?
A. 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.

Q. Why does the max flow rate reduce when the pipe size increases?
A. Micronics 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.

Q. I have negative separation distance, how is this possible and how do I fix it?
A. This is obviously not practical. It may be possible to force the unit into double or triple bounce to increase the separation distance.

Q. I seem to be getting lower flow readings with Stainless steel pipes?
A. 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.

Q. If I need to use a liquid other than water how does this change things?
A. Select from the list of liquids programmed into the unit. If the liquid you are measuring is not in the list, use the tables at the back of the manual for the correct speed of sound for your particular application.

Q. What effect does extending the sensor cables have?
A. The sensors are supplied as matched pairs. As long as the cables are the same length anything up to 50 metres in length will not be a problem.

Flow Meter FAQs – Battery and Power

Q. Unit doesn’t switch on?
A. Check power supply – use a multimeter to make sure this is working? Is the battery charged? Is the charger working?

Q. How long do the batteries last?
A. Anywhere between 4-36 hours depending on the instrument.

Q. How long does it take to charge?
A. This also depends on the instrument; please refer to the manual supplied with the unit.

Q. Can I use the unit with an external battery?
A. Micronics supply a 9-12volt converter, to enable the user to connect the units to an external battery (e.g. car battery).

Q. How can I dispose of the battery?
A. Disposal requirements for batteries can vary from country to country. Please contact your local government for disposal or recycling practices in your area.

Q. Can I remove the battery from the unit to charge it up?
A. No. The battery needs to stay connected in the unit to be charged.

Flow Meter FAQs – Calibration

Q. How often does the unit need to come back for calibration?
A. Portable units have a 12 month calibration certificate and should be returned to Micronics each year.

Q. Do I need to return the sensor set with the instrument in order for it to be calibrated?
A. Micronics 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.

Flow Meter FAQs – Datalogging and Download

Q. Which flowmeters have dataloggers?
A. Utraflo 4000 and Portaflow 330 models only. Other units can connect either the 4-20mA or pulse outputs to an external data logger.

Q. What is Hyperterminal?
A. Hyperterminal is a piece of software that is provided with older 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.

Q. How do I download data from my Portaflow 300/330/SE?
A. This procedure is explained in the instruction manual.

Q. What is the memory size in the Portaflow 300/330/SE? How much data will be stored?
A. The data logger in the PF300 and PFSE has a 50000 point memory size, the PF330 has a 98,000 point memory size.
One set of information – date, time, flow, units equates to one data point.

Q. How many different locations can I record?
A. 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.

Q. How long will the logger last?
A. 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.

Q. I’m having problem downloading data? What am I doing wrong?
A. Check that the RS232 cable is not faulty and plugged in, follow the procedures in the relevant manual for your device.

Q. My battery has just run out, will I lose all the data and how do I get it back?
A. 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.

Flow Meter FAQs – Guiderail and Sensor Issues

Q. Can I use several sensors with one set of electronics?
A. No.

Q. How much grease or couplant do I use on each transducer?
A. 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.

Q. Can I use the sensors on vertical and horizontal pipes?
A. 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.

Flow Meter FAQs – Installation and Commissioning

Q. What service do Micronics offer?
A. Micronics can carry out installation and commissioning works in the UK. Generally however, the customer will install the unit and Micronics will commission it.

Q. If the customer installs the U3000 unit what is expected?
A. 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.

Q. What considerations do I need for mounting the Ultraflo 3000 transmitter?
A. 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. Micronics 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.

Q. What considerations do I need for mounting the Ultraflo 3000 sensors?
A. 10-15 pipe diameters up and downstream of flow sensors – see manual for further info.

Q. What considerations do I need for mounting the Ultraflo 3000 heatmeter PT100 probes?
A. 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.

Flow Meter FAQs – Outputs

Q. What type of pulse outputs do the units give? What output/voltage?
A. The pulses are from a solid state relay, maximum 1 pulse per second, 0-5V and are not frequency pulses.

Q. Is the 4-20mA output loop powered? Will it drive another system?
A. No. The line will need to be powered by other means.

Q. What is the max impedance/load you can put on the 4-20mA output?
A. The 4-20mA chip is driven by 15V. Therefore the max load you can have on the circuit at 20mA is 750Ohms. If the error or fault condition output is set to 22mA then the impedance is 680Ohms.

Q. What does the pulse output do when the flow reverses?
A. It stops working. The pulse only works when the flow is forward.

Q. What output signal can we have if the flow reverses?
A. 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.

Flow Meter FAQs – Miscellaneous

Q. The processor is corrupted and the unit needs to be re set.
A. 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, 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.

Flow Meter FAQs – Signal Problems

Q. No signal/Poor signal? What do I do?
A. 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 that the sensors are on the side of horizontal pipes and not on the top.

Q. What is a poor signal and what effect does this have on the accuracy/reading?
A. Signals below 30% are low and may affect the readings. Signals below this level will also not record TOTAL values.

Q. My unit is displaying an error message what does it mean?
A. 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 faces.
3. The pipe may be partially empty, aerated or have a high particulate content.

Q. I’m getting the Error message “High flow” but the signal is showing 50%?
A. This can be associated with velocities that are higher than can be measured by the instrument, excessive turbulence or entrained air in the system.

Flow Meter FAQs – Transit Time Products

Q. Can the application be altered to modify pipework and allow for an ‘always flooded section’ of pipe?
A. Yes, as long as the pipe stays full. U bends are possible but if it is not long enough it could affect accuracy.

Q. What liquids can be measured?
A. Transit time meters can measure most liquids as long as they are free from entrained air and solids.

Q. What liquids cannot be measured?
A. It is not possible to measure Hydrofluoric acid or Polyurethane


Q. Can the internal Portaflow 300 battery be upgraded to provide longer battery life?
A. The internal charging circuitry on the Portaflow 300 is matched to the factory supplied battery and therefore cannot be swapped for a higher capacity unit. Using an external battery connected via a 9-12Vdc adaptor available from Micronics to the 9Vdc input on the portaflow 300 will extend it’s independence of operation. Please refer to your manual for detailed instructions on how to do this.


Q. What is the flow range of the Portaflow SE?  
A. The flow range depends on the pipe size and mode of operation. On a 50 mm pipe in reflex mode, it’s 0.3 m/sec up to 6 m/sec. On a 1000mm pipe its 1.3 m/sec in diagonal mode. It really depends on the pipe size.


Q. What is the accuracy of the Portaflow 216? 
A. The accuracy is 1-3% of the reading, within the velocity range specified.


Q. What is the password to get into the UF2000? 
A. Press Function key and enter 2000

Q. I’m getting signal of 50% but the unit is displaying error message E1.  
A. When the instrument is programmed the user is informed of the maximum flow rate that the instrument can measure. If this is exceeded the High flow message occurs.

It may be possible to get round these problems by using another set of transducers in another mode. This should not be necessary as the unit would have been supplied for a particular application with the correct transducers.


Q. Can the UF2000 be used with more than one set of transducers?
A. No, each application needs one Ultraflo 2000 system.

Q. Does the UF2000 come with a datalogger?
A. No, however the pulse or 4-20mA outputs may be used with an external logger.

Q. Heatmeter is reading zero energy, but I know I have a flow? 
A. Check the temperature difference readings. Check that the pipe is full and the fluid is free from entrained air and solids. Make sure that there is sufficient grease on the transducers.

Q. Totaliser resets when I change units from kW to ºC? 
A. The totaliser is designed to reset when changing from kW to flow.

Q. What formula is used to measure the energy?
A. The formula used to measure the energy is: Flow x temperature difference x specific heat.

Q. I get a pulse when in flow mode but not in energy mode?
A. The Ultraflo 2000 has one pulse output. If the pulses have been set up for flow, the pulses will need to be reset for energy mode. Follow the instructions in the manual for the setup procedure.


Q. Values entered are rejected or ignored by the interface 
A. When the mouse cursor is hovered over an entry box where there are limits to the values that may be entered, these limits will be displayed. If values are entered that are outside these limits, the GUI will reject them. In doing so it may change the original value to a maximum or minimum default.
If you cannot enter a value that you believe should be valid please contact Micronic

Q. Red indicator on the GUI panel 
A. Check that the RS232 lead is connected correctly and that you have power (U100 green LED on)(see next question).

Q. Red light on the U100 box. 
A. This could mean the signal level has dropped or the outputs are scaled incorrectly. Connect a PC that has the U100 software installed to what the error message is in the GUI Terminal window.

Q. No lights on the U100 box 
A. This could mean the signal level has dropped or the outputs are scaled incorrectly. Connect a PC that has the U100 software installed to what the error message is in the GUI Terminal window.

Q. How do I know if the U100 is working?
A. On the lid, the green LED will be on, the red LED will be off. There will also be data output stream on the RS232 connector – two bursts every second.

Q. How do I connect the U100 to a data logger?
A. Either via RS-232 or 4-20mA; refer to the data logger’s instructions.

Q. How do I log the data? 
A. Refer to the instructions of your data logger (this refers to your own data logger, there is no data logger provided by the U100 or GUI). If using a PC, running a program like Terminal (for Windows) or HyperAccess, select Transfers –Capture Text – save OK – Stop (when finished logging). Then open that text file with Excel, edit and plot it. (See Excel Help).

Q. How do I connect the U100 to my building management system? 
A. That depends on what the BMS requires. The U100 outputs are: RS232, Pulse and 4-20mA.

Q. What happens when the flow stops?
A. The instrument will read 0.0 or a very small zero offset value, which can be suppressed by setting the zero cut off higher.

Q. How long does the guarantee last? 
A. 12 months from the issue of the invoice or 18 months if the extended warranty form has been returned to Micronics.

Q. When do I send the U100 back for calibration? 
A. Micronics recommend re-calibration at twelve month intervals.

Q. Can I operate the U100 using a battery? 
A. Yes, connect an 18V – 28V battery to the 24Vdc input.


Q. I am getting the error message E: ILLEGAL MaxF.
A. The value entered for MaxF (maximum flow) is too low or too high.
Maximum flow value must compute (using pipe ID) a velocity greater
than 0.25 ft/sec (0.076 m/sec) or less than 40.0 ft/sec (12.2 m/sec). Refer
to Appendix B – Conversion Tables to convert from volume to velocity


Q. The pipe vibrates. Will it affect the flow meter?
A. Common vibration frequencies are far lower than the ultrasonic frequencies used by the Greyline flow meter, and will not normally affect accuracy or performance. However, applications where very weak Doppler signal is present (when sensitivity is adjusted to maximum and signal strength is low), accuracy may be affected by pipe vibration, or the flow meter may show readings under no-flow conditions. Attempt to relocate the sensor on a pipe section where vibration is reduced, or arrange pipe mounting brackets to reduce vibration at the sensor mounting location.

Q. Can the sensor be submerged in water? 
A. Yes, for short periods of time or by accident, but not for continuous operation. The sensor is constructed to withstand submersion to 10 psi without damage, but external liquid moving in contact with the sensor can be interpreted as flow and cause false readings.


Q. How does the sensor stay in the pipe? 
A. The sensor attaches to a ring that is sized to the application and opens up inside the pipe. It has a stud that goes through the hole in the sensor to hold it in place. The rings are available from Micronics.

Q. Is logger memory retained with batteries removed and Stingray Off? 
A. Yes, logger memory is maintained with Stingray batteries removed. The only way to delete logger memory is through Greyline Logger software Real-Time display and clicking Write.


Q. How does the sensor stay in the pipe? 
A. The sensor attaches to a ring that is sized to the application and opens up inside the pipe. It has a stud that goes through the hole in the sensor to hold it in place. The rings are available from Micronics.

Q. I am getting the error message: Er: ILLEGAL UNITS 
A. Your choice of UNITS exceeds a maximum value of 9,999,999. Use US MGD, Imp MGD or m3/d so that UNITS will be 9,999,999 or less.


Q. I am getting the error message: Er: ILLEGAL MinRg 
A. The value entered for MinRg (Minimum Range) is less than 8″ (20.3 cm). MinRg must be greater than or equal to 8″ (20.3 cm) for PZ12 sensors. Minimum Range for PZ32T sensors must be _ 12″ /30.5 cm.


Q. I am getting the message: NORMAL / REVERSED SET POINTS MIXED! 
A. Relays have been selected for Pump Alternation and have been calibrated in opposite modes. Any alternating relays must be calibrated in the same mode:
1. with ON setpoint > OFF setpoint, or

2. with OFF setpoint > ON setpoint


Q. The display is showing no ECHO, what does this mean? What can be done? 
A. The instrument has not sensed a valid echo for 10 seconds. Refer to your manual for the correct installation placement for the sensor assembly.


Q. The Relay Operates When There Is No Flow 
A. This could be because the “ON” or “OFF” points are set to less than 0 ft/sec, there is vibration on pipe, local electrical noise or the relay mode is set to FAILSAFE


Q. The relay does not operate
A. There may have been a power interruption or improper power input, improper installation of the sensor, the sensitivity is set too low or there is low flow noise.


Q. The Alphanumeric display (bottom display) blinks continuously as if power was being turn off and on (i.e instrument resets continuously).
A. This could be a symptom of RFI produced by relay activation. When relay contacts are used to switch inductive loads, such as auxiliary relays or solenoids, extremely large voltage spikes can be generated when the relay contact opens producing what is known as Radio-Frequency Interference or “RFI” or just “noise”. It is recommended that electronic instruments be connected to a relatively clean AC power source. Use an AC power filter or isolation transformer if necessary.


Q. What is the setup password?
A. 71360


Q. What is the setup password? 
A. 71360

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