Help needed in identifying the sensor - Page 1
Forum section: electronics / beginners

author: deepak.midri
author_rank: Newbie
timestamp: June 21, 2014, 05:17:42 am
content: I am using ultrasonic milk analyzer machine & i nee to identify what is the sensor.http://www.eonbg.com/ultrasonic-milk-analyzers/milkanalyzer-ekomilk-ultra.html#4-user-manualI have attached pics of sensor. It gets broken.Page 1 & Page 3 are the two sensor at two ends of tube.Tube is shown in Page 2. Tube is broken.

author: sfiber
author_rank: Regular Contributor
timestamp: June 21, 2014, 05:34:49 am
content: Woow,I wonder too what it is.actually its not look like a sensor

author: What_NZ
author_rank: Regular Contributor
timestamp: June 21, 2014, 06:09:29 am
content: Looks like a Piezo sensor in the centre and it is being used to measure pressure, most likely?

author: What_NZ
author_rank: Regular Contributor
timestamp: June 21, 2014, 07:08:36 am
content: I see that that the Product information mentions "Ultrasonic Technology" so one could be a Ultrasonic transmitter and the other a receiver?The wire wrapped around the tube is a heating element?

author: SeanB
author_rank: Super Contributor
timestamp: June 21, 2014, 07:17:09 am
content: I would take a guess that the coil is doing something to a magnetostrictive ferrite, and this is transmitted to the milk and used to get a resonant pulse that is dependant in things like temperature ( likely read by a thermistor) and then the piezo discs on the ends read the oscillation to get the amplitude and such, which will be a function of the density of the surrounding fluid. Thus with the density and temperature you can calculate the amount of fat in the mix, thus giving butterfat and water content. Likely the piezo strips are used to do do a simple speed of flight to compensate the long rod, and the brass core is used to detect ionic concentration by the loss from eddy currents in the liquid.But, without knowing the materials the ferrite is made from, you will not be able to copy the sensor, and will have to buy a new one. The materials are not likely to be off the shelf ones, and will probably be a proprietary blend especially made for the application.

author: What_NZ
author_rank: Regular Contributor
timestamp: June 21, 2014, 07:27:46 am
content: Quote from: SeanB on June 21, 2014, 07:17:09 amYeah everything you said....... I feel very humble (i.e. I learnt something) Sounds like you are familiar with such sensors?

author: deepak.midri
author_rank: Newbie
timestamp: June 21, 2014, 07:55:45 am
content: I was reading :http://www.dispersion.com/ultrasound-for-characterizing-liquid-based-food-productsIt says:Figure 1 illustrates the main principles of the "transmission" approach.Piezo-crystal transmittergenerates ultrasound pulse of certain frequency and intensity and launches it into the sample. Intensity of pulse decays due to the interaction with the sample.Piezo-crystal receivedconverts this weaker pulse back to electric pulse and sends it to electronics for comparison with the initial pulse. This means that intensity of the pulse after propagation through the sample is a raw data.I was looking for sensor where I can buy.still searching..............

author: SeanB
author_rank: Super Contributor
timestamp: June 21, 2014, 08:19:57 am
content: Quote from: What_NZ on June 21, 2014, 07:27:46 amNo, never met them apart, but have seen and used industrial sensors that used ultrasonics to detect levels in tanks and in clumping materials, either by measuring the volume above the tank with reflection or by looking from below to get the liquid/air interface. Plenty used a magnetostrictive generator as it is capable of very high power output and only needs low voltage drive. Piezoceramic is a very high impedance material, and needs very high voltage drive, but makes a very sensitive receiver instead.

author: deepak.midri
author_rank: Newbie
timestamp: June 23, 2014, 10:07:51 am
content: yes they are piezo sensor as explained in website:http://www.dispersion.com/ultrasound-for-characterizing-liquid-based-food-productsI need to identify these sensor, anyone knows