sensor solutions /// sdt shielded piezo sensors rev 1 9/2015 page 1 dimension in inches (mm) a film b electrode c film d electrode t ( m) cap (nf) .640 (16) .520 (13) 1.64 (41) 1.18 (30) 75 2.78 sdt shielded piezo sensors specifications ? shielded coaxial cable lead ? shielded sensor ? low noise ? flexible ? multi-purpose ? piezo film technology the s in sdt stands for shielded sensor. sdt1 piezo film sensors consist of a rectangular element of piezo film together with a molded plastic housing and 18 of coaxial cable. the film element, screen printed with silver ink, is folded over on itself, providing self-shielding of the transducer area. this is important in applications in high emi environments. the sdt1 can be adhered to other surfaces using double sided adhesives, epoxy or cyanoacrylate (super glue). care should be taken if the sensor is to be removed, as the double-side adhesive can peel the metallization from the film. when adhered to a surface in this manner, the sdt1 is an excellent contact microphone or dynamic strain gage. the output from the sdt1 can input directly to an oscillosco pe (10 m preferred input impedance) or a signal analyzer. features ? shielded piezo film sensor ? high longitudinal strain coefficient ? integral coax cable ? wide frequency response applications ? machine monitoring ? acoustic emission detection ? contact microphone ? vibration / impact sensing ? detecting machine tool chatter ? acoustic pickup ? vibration analysis for equipment and product design dimensions
sdt shielded piezo sensors sensor solutions /// sdt shielded piezo sensors rev 1 9/2015 page 2 instructions using a double-sided adhesive tape, adhere the sensing element to the vibrating objec t. the adhesive tape should have a thin and non-foam type carrier. a double-sealed tape, such as 3m ? 444, works well. clean off the surface of the object upon which the sensor is to be placed, removing an y foreign particles such as dirt, dust, grease, etc. then apply the adhesive tape to the clean surface. next, adhere th e sdt1-028k to the adhesive by attaching the end of the sensor element first and smoothing out the e lement (avoiding any creases or air bubbles) towards the lead attach. the adhesive must continue out and hold down the plastic lead attachment housi ng as well, to prevent errant results. similarly, it is recommended that the wire be taped down in some instances ( this can be done with masking tape in a designated position). if the sensor is to be used in an environment above 45c [114f], then a different adhes ive system is recommended since the double sided tape can become soft and affect the sen sor's ability to detect vibration. cyanoacrylate or a five-minute epoxy are useable, but they are permanent. the leads can be connected directly into an oscilloscope or frequency anal yzer with preferably, a 10 m? impedance. sensor operation operating in a reciprocal fashion, changes in length generate a corresponding charge and hence, voltage to appear on the electrodes of the film. the transducer behaves like an active capacitor, consequently, loading of the signal by the input impedance of the measuring device must be considered. due to the thinness of the films, the associated capacitance can be sufficient to give adequate low freque ncy response into standard 1 m? loads, but use of an x10 probe will extend the low frequency range by a decade. for ex tremely small devices and low frequency vibration levels, some buffering may be desirable. for the majority of a nalysis work, this is unnecessary and the film can feed directly to the instrument. the low mass contributed by the transducer is of major importance, and its no n-resonant behavior. frequency response is inherently flat into the mhz region with only the r-c roll off at low frequencies distorting the profile . since it is responding to strain rather than acceleration, high signal levels may be generated by low frequency flexing, so a distinction must be made between the frequency response of the f ilm for changes in its primary parameter (i.e., strain) and its relative behavior compared with, say piezoelectric ac celerometers. the response of the sensor to strain enforces its likeness to a strain gauge, but with much higher output. the sensor performs well at low frequencies where displacement is large and accel eration low, as well as at high frequencies where displacement is small and acceleration high. the sensor has a flat response over a very wide frequency range, with resonant frequency points above 10 mhz. sdt1-028k low frequency response -36 -30 -24 -18 -12 -6 0 6 1 10 100 1000 10000 100000 frequency (hz) magnitude (db) r = 1 m ohm r = 10 m ohm
sdt shielded piezo sensors sensor solutions /// sdt shielded piezo sensors rev 1 9/2015 page 3 performance specifications minimum impedance 1 m? preferred impedance 10 m? output voltage @ 10 m? min 15 v storage temperature -40c to +70c [-40f to 160f] operating temperature 0c to +70c [32f to 160f] (depending on adhesive system). for more stringent, high operating temperature requirements, special preparation of the sensor can be arranged. operating force range up to 2% strain output 15 - 20 mv/ strain circuit connection red wire-signal white/braided wire-ground physical characteristics wire length 457.2 mm [18 in.] total sensor length/width/height 44.5 x 19.7 x 3.2 mm [1.75 x .775 x .125 in.] sensor element length/width/height 28.6 x 11.2 x .13 mm ordering information description model no. part no. sdt shielded piezo sensor sdt1- 028k 1-1000288-0 te.com/sensorsolutions measurement specialties, inc., a te connectivity company. measurement specialties, te connectivity, te connectivity (logo) and every connection counts are trademarks. all other logos, products and /or company names referred to herein might be trademarks of their respective owners. the information given herein, including drawings, illustrations an d schematics which are intended for illustration purposes only, is believe d to be reliable. however, te connectivity makes no warranties as to its accuracy or completeness and disclaims a ny liability in connection with its use. te connectivitys obligation s shall only be as set forth in te connectivitys standard terms and conditions of sale for this product and in no ca se will te connectivity be liable for any incidental, indirect or consequential damages arising out of the sale, resale, use o r misuse of the product. users of te connectivity products should make their own eva luation to determine the suitability of each such product for the specif ic application. ? 2015 te connectivity ltd. family of companies all rights reserved. north america measurement specialties, inc., a te connectivity company 1000 lucas way hampton, va 23666 sales and customer service tel: +1-800- 745 -8008 or +1 -757-766-1500 fax: +1-757-766-4297 technical support email: piezo@meas-spec.com europe meas deutschland gmbh a te connectivity company hauert 13 44227 dortmund germany sales and customer service tel: +49 (0)231 9740 21 technical support tel: +49 (0)6074 862822 email: piezoeurope@meas-spec.com asia measurement specialties (china), ltd., a te connectivity company f1.6-4d, tian an development compound shenzhen, china 518048 sales and customer service tel: +86 755 8330 1004 technical support email: piezo@meas-spec.com
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