FAQ

A minimum distance from the face of the transducer where a measurement cannot be taken. It can also be referred to as dead band or ring down. The blanking distances for the transducers are shown in the respective literatures on our website.

You can mount the Ultrasonic transducer up to 1 km away (or further) from our controllers (or 500m for radar) in most situations and in many applications cables can be extended via way of a junction box. Exact separation distances and cable requirements are contained within the relevant product literatures on our website.

You should select a radar sensor over an ultrasonic one for applications with high temperatures, applications subject to foam or atmospheric changes, or applications with harsh chemicals that give off vapours.

3 x 0.5mm2 with a foil screen to match the transducer. Or as a minimum a twisted pair with overall screen.

If the cable has 3 cores then the answer is yes. If the Coaxial cable has an outer sheath so you have the inner core, braiding and an outer sheath it will be ok.

This is the measurement from the face of the transducer (end of the horn for a dBMach3) to the empty point of the vessel being measured.

Pulsar controllers have a software within them known as DATEM- Digital Adaptive Tracking of Echo Movement. What this essentially means is that a Pulsar controller can be taught to ignore false echoes and focus only on the true level. This means that our transducers have an effective beam angle of < degrees inclusive!

Use the Ultra Wizard menu to set the controller to Pump Control mode.

Controllers with firmware prior to version 7.0.7 may be susceptible to this fault. It can be rectified by Upgrading the controller firmware via the PC suite software.

No, only Pulsar Transducers can be used with Pulsar Controllers

Filtering algorithms within the controller firmware prevent crosstalk between systems, but it is best practice to mount separate systems as far apart as reasonably practicable

Area x Velocity is a type of 'open channel measurement' where a 'primary measuring device’ is not used but instead the water velocity is measured and multiplied by the cross-sectional area of the channel - calculated from the measured 'head' and the channel's profile.

The lower, smaller digits on the LCD display for Ultra units.

An analogue input fitted to an Ultra controller so that a 4-20mA loop powered sensor can be used in place of an ultrasonic transducer, or to allow the input from velocity sensor in 'open channel measurement'.

The beam angle is the inclusive angle about the central axis of the sound pulse where the emitted sound level has reduced by 3dB compared to the sound level on the axis at the same distance from the transducer.

BS3680 is the British Standard for 'open channel measurement' defines certain types of flumes and weir, their installation and the calculations required to get a flow rate from a measured 'head'.

Digital Adaptive Tracking of Echo Movement - Pulsar's unique and proven digital mapping software which tracks the true echo as it moves whilst dynamically eliminating false echoes.

Some units in our Ultra range allow connection of two transducers. This enables calculation of the difference (differential) between two levels in order to view or provide control functions from it.

Echo confidence is a measurement of the reliability of the current reading. 100% indicates that there are no competing echoes. Lower values may indicate that the unit is choosing the 'best' of two or more echoes.

When a 'loss of echo' condition persists, the controller will indicate fail safe and take any actions that have been pre-programmed for relays and analogue outputs. You should check the measurement path of the transducer is clear and contact the Pulsar Measurement Support Team for help.

‘Far Blanking’ is the zone beyond the 'empty distance' where valid echoes can still be detected, normally expressed as a percentage of the 'empty level'.

A flume is often made from Stainless Steel, concrete or GRP and installed into a straight channel so that 'open channel measurement' can be made using measurement of the 'head' only. A type of 'primary measuring device'.

Height Above Loss Limits - an indication of the height of the tracked echo above the threshold for valid echoes.

This means the transducer and controller cannot detect a valid echo trace, you should check the measurement path of the transducer and check the face of the transducer is clean. Contact the Pulsar Measurement Support Team for help.

Program mode is accessed by entering the password 1997 (default), measurement readings are suspended while parameter values are changed.

Quick set up is a handy menu which guides the user through only the parameters that are necessary to set up their particular application. Just enter the application details as they are requested to get the unit up and running fast.

‘Run Mode’ is the normal mode of operation when the transducer is pulsing and the display indicating as programmed.

The Span sets the difference in level between empty and full and defines the 4-20mA values for the analogue output.

Air temperature changes will affect the speed of sound and therefore the accuracy of any ultrasonic measurement system. Pulsar transducers incorporate an internal sensor which measures the temperature at the transducer and automatically reduces any inaccuracy. Some systems will have a separate sensor if the temperature at the transducer is not representative of the whole 'sound path'. Pulsar's unique DUET transducer dynamically measures the sound velocity and thereby achieves even better accuracy over changing climate conditions.

Yes, some units can simulate a level to allow the testing of relays and analogue outputs with connected equipment. (See P980 in your manual if available).

Time of flight is the time taken for the sound to travel from the transducer to the target and back.

Pulsar controllers are capable of a huge range of functionality. To make set up easier and quicker we've added the Ultra Wizard to enable you to configure a unit quickly for three basic application types (where available): Level/Volume, Pump Control or 'OCM'. 'Quick Setup' takes you through the rest.

A weir is a specifically shaped barrier or cut out in a plate installed in a channel or tank so that 'open channel measurement' can be made by measurement of the 'head' only. A type of 'primary measuring device'.

Zero Flow is the level of water in a flume or over a weir at which no flow takes place i.e., level with the crest of the weir or flume (not necessarily equal to the empty distance).

Common vibration frequencies are far lower than the sonic frequencies used by the flow meter, and will not normally affect accuracy or performance. However, applications where very weak Transit Time 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.

Our flow meters are designed to discriminate between environmental noise and the Transit Time signal. High noise environments may affect the flow meter’s performance where low signal strength and/or low flow velocities are being measured. Relocate the sensor in a quieter environment if possible.

Yes. Rust, loose paint etc. must be removed from the outside of the pipe to provide a clean mounting position when installing a Transit Time sensor. Severe corrosion/oxidation on the inside of the pipe may prevent the Transit Time signal from penetrating into the flow. If the pipe cannot be cleaned, a spool piece (PVC recommended) should be installed for sensor mounting.

The air gap between loose insertion liners and the pipe wall prevent the Transit Time signal from entering the flow. Better results can be expected with bonded liners such as cement, epoxy or tar, however an on site test is recommended to determine if the application is suitable for a Transit Time flow meter.

The Transit Time sensor transmits sound across the flow stream in order to measure the time it takes to arrive at the other sensor, and therefore requires a fluid medium that is relatively transparent to the acoustic signal. The Transit Time system will not function when there is high volume of solids or aeration. As a guideline, Transit Time flow meters are recommended for clean liquids with solids or bubbles content less than 2% by volume

Yes, for short periods of time or by accident, but it is not recommended for continuous operation. The sensor is constructed to withstand submersion to 10 psi (0.7 Bar) without damage provided the protective rubber boot is filled with Super Lube®.

The primary function of the signal strength display is to assist as a feedback when mounting sensors. Signal Strength can also be a useful diagnostics tool when troubleshooting problems with an installation. A signal strength less than 100% may indicate a problem with the installation or other issues such as a mis-programmed pipe size, pipe material, fluid type or temperature, or wrong transducer spacing. A signal strength less than 100% may also simply indicate a lot of aeration, or deteriorated pipe. Consideration should be made to use a 1 cross installation in such a case.

Yes. The Transit Time design allow cable lengths up to 100 ft (30 m) or extension up to 250 ft with extra cable and JB2X optional junction box. Replacement cable of different length may be installed in rigid or flexible conduit for mechanical protection. Use only our shielded triaxial cable.

TTFM 6.1 calibration does not drift over time. The solid state sensor has no moving parts to wear and affect calibration. All timing/counting circuits use crystal-controlled frequency references to eliminate any drift in the processing circuitry. ISO 9000 or similar quality management systems may require periodic and verifiable recalibration of flow meters. TTFM 6.1 Flow Meters may be returned to Pulsar Measurement for factory calibration and issue of a new NIST traceable certificate. Refer to the ‘Product Return Procedure’ section of this manual for return instructions.

Our flow meters are designed to discriminate between environmental noise and the Doppler signal. High noise environments may affect the flow meter’s performance where low signal strength and/or low flow velocities are being measured.

The air gap between loose insertion liners and the pipe wall prevent the Doppler signal from entering the flow. Better results can be expected with bonded liners such as cement, epoxy or tar, however an on site test is recommended to determine if the application is suitable for a Doppler flow meter.

The Doppler sensor transmits sound into the flow stream which must be reflected back to the sensor to indicate flow velocity. Gas bubbles or suspended solids act as reflectors for the Doppler signal. As a guideline, our Doppler flow meters are recommended for liquids containing solids or bubbles with a minimum size of 100 microns and a minimum concentration of 75 ppm. Most applications (except potable, distilled or deionized water) will meet this minimum requirement.

Yes, for short periods of time or by accident, but it is not recommended 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.

Doppler signals of very low strength are not accepted or processed by the instrument. This feature assists in rejection of environmental noise and vibration. Use the display to evaluate signal strength in your application. Strong signals will increase in percentage to a maximum of 100% or greater.

Yes. Our Doppler’s design allow cable lengths up to 500 ft (152 m) with no loss of signal strength. Extended cable (Option DXC) should be installed in rigid or flexible conduit for mechanical protection. Use only our shielded coaxial pair (RG174U) cable. Cable junctions should be made through a terminal block and housed in a watertight metal junction box (Option ‘JB2X’). BNC coaxial connectors (TV cable type) are not recommended for cable splices.

DFM 6.1 calibration does not drift over time. The solid-state sensor has no moving parts to wear and affect calibration. The Doppler flow technique generates an ultrasonic signal proportional to the velocity of flow. All timing/counting circuits use crystal-controlled frequency references to eliminate any drift in the processing circuitry. ISO 9000 or similar quality management systems may require periodic and verifiable recalibration of flow meters. DFM 6.1 Doppler Flow Meters may be returned to Pulsar Measurement for factory calibration and issue of a new NIST traceable certificate. Refer to the ‘Product Return Procedure’ section of this manual for return instructions.