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Unilenght Meter for Yarn Speed & Length Measurement

The Unilength Meter is an instrument that measures both yarn speed and Yarn length, specifically for use on circular knitting machines. The instrument consists of a battery powered control unit, a measuring head and a probe that automatically starts and stops length measurement. The batteries are rechargeable (battery charger also supplied) and the use of the latest solid state technology gives a long battery life between charging.

Using the Unilength Meter enables rapid quality control checks for both stationery and rotating cam box machines and for faster setting of machines to quality. Control checks on course length can be made during production without the labour costs involved in unroving. There is also no re-calibration required for this instrument because of the measurement method used.

Measuring Head

The Unilength Meter measuring head uses a rotating wheel that has Very light bearings to ensure there is no introduction of tension into the yarn when measuring. The head is easily inserted into the running yarn path and with the combination of the measuring wheel and a yarn guide a simple turn of the head through 90 degrees makes contact between the rotating wheel and the yarn. The head is plugged into the control unit via a 1 Metre coiled lead and when the measuring wheel rotates electronic pulses are generated and feed to the control unit via the connecting lead.

Probe

The Unilength Meter 'Probe' is only required when measuring yarn length. The probe provides the information the control unit requires to start and stop measuring. The 'Probe' comes in two types, a permanent type and a micro-switch type. The micro-switch probe can be moved from machine to machine where as the permanent type fixed permanently to the machine, as the name would suggest. The permanent probe uses a Hall Effect switch and a magnet. The magnet is mounted onto the moving part of the machine and the Hall Effect switch is positioned so the magnet passes it, upon the magnet passing this switch an electronic pulse is sent to the control unit. The micro-switch type is mechanical and is positioned so that the switch lever makes contact with the moving part of the machine when it passes the switch, this makes and breaks the switch contact thus providing the required pulse to the control unit.

Control Unit

The Unilength Meter Control Unit has a switch to select between speed and length measurement. When measuring speed all that is required is to plug the measuring head into the control unit, select the speed measurement mode and insert the head into the running yarn path. The 4-digit LED display will indicate the speed of the yarn in Metres per minute, up to a maximum of 1000 M/Min. To measure length the Unilength Probe generally used to start and stop the measurement but there is a facility to manually start and stop length measurement. Using the manual method relies upon the operator to press a button to start the measurement and to press it again to stop the measurement, this function is only useful as an indication of length and is only as accurate as the operator can make it. When accuracy is required then the probe is to be plugged into the Control Unit, and to check the probe is working correctly an LED is provided on the Control Unit. The LED flashes, ON when the probe has been activated, this means that the electronic pulse to start and stop measurement is reaching the Control Unit. With the length measuring mode selected, the measuring head and probe connected to the Control Unit the measuring head is inserted into the moving yarn path. When the probe has been activated the 4 digit LED display will display the length being measured and when the probe is activated again the Control Unit stops measuring and the figure on the LED display is the length measured in Cm (maximum 9999). This figure will remain on the display until the probe is activated again, when this happens the display is cleared and the Control Unit starts to measure the length again until the probe is again activated. This cycle of events will continue until the measuring head is removed from the yarn path or when the probe is disconnected from the Control Unit. There is one more feature on the Control Unit, Low Battery Indication. This feature works when the unit is first switched on and it utilises extreme right hand decimal point on the LED display. Only when switching on the unit is when the batteries are checked, if the decimal point is bright then the batteries are o.k. but if it is dim then the batteries should be charged. When actually using the meter the decimal point will look dim but this does not indicate the batteries need charging, only when the meter is switched on should notice be taken of the brightness of the decimal point.