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The element

BLT transducers — single frequency

A bolt-clamped Langevin transducer is the piece that actually makes the sound: a piezo stack clamped between a metal front mass and back mass, tuned to one frequency. It is what sits inside an immersible box or bonds to a transducer plate.

Each element is tuned to one note. An element that has to run a coarse pass and a fine pass is a dual-frequency element.

We sell them as elements — for building plates, for OEM machines, and for repairing a tank whose bonded array has gone deaf rather than scrapping the vessel.

The Misonics VarioSonic single-frequency transducer range, 20 kHz to 130 kHz
The single-frequency range, 20 kHz to 130 kHz. Shown to scale — the higher the frequency, the smaller the element.
The elements

Frequency by frequency

Frequency is chosen by the deposit and by what the substrate will take — 20 kHz for the heaviest work on robust steel, 28 kHz for scale and hard carbon, 40 kHz for general engineering, 68 kHz where the finish matters, 80 and 130 kHz where it barely matters at all. Power is the rating of one element; a plate or box carries several. Elements are not held in stock — they are supplied against a firm order, with the lead time advised at quotation.

BLT ultrasonic transducer, 50 W at 20 kHz50 W · 20 kHzThe heaviest work — thick scale and heavy carbon on robust steel. Also made at 100 W.Enquire →BLT ultrasonic transducer, 100 W at 28 kHz100 W · 28 kHzThe heavy element — scale, hard carbon and weld deposit.Enquire →BLT ultrasonic transducer, 60 W at 28 kHz60 W · 28 kHz28 kHz at lower power, for smaller plates and tighter packing.Enquire →BLT ultrasonic transducer, 60 W at 40 kHz60 W · 40 kHzGeneral engineering work and a better surface finish.Enquire →BLT ultrasonic transducer, 60 W at 68 kHz60 W · 68 kHzFine and precision work where the substrate will not take a heavy band.Enquire →Single-frequency ultrasonic transducer element, 60 W at 80 kHz60 W · 80 kHzFine particulate off plated, polished and delicate surfaces. 60 W per element; dimensions confirmed at quotation.Enquire →Single-frequency ultrasonic transducer element, 50 W at 130 kHz50 W · 130 kHzThe gentlest band we supply — sub-micron particulate, optics and coated surfaces. 60 W per element; dimensions confirmed at quotation.Enquire →

Element count, spacing and bonding are specified against the plate or the vessel. Dimensions and mounting detail are confirmed at quotation.

Specification

By part number

Part numberFrequencyPowerWhat it is for
MS300-20kHz-50W20 kHz50 WThe heaviest work — thick scale and heavy carbon on robust steel
MS300-20kHz-100W20 kHz100 W20 kHz at full power, for the largest plates
MS300-28kHz-100W28 kHz100 WThe heavy element — scale, hard carbon and weld deposit
MS300-28kHz-60W28 kHz60 W28 kHz at lower power, for smaller plates and tighter packing
MS300-40kHz-60W40 kHz60 WGeneral engineering work and a better surface finish
MS300-68kHz-60W68 kHz60 WFine and precision work, where the substrate will not take a heavy band
MS300-80kHz-60W80 kHz60 WFine particulate off plated, polished and delicate surfaces
MS300-130kHz-50W130 kHz50 WSub-micron particulate, optics and coated surfaces

All of these are bolt-clamped Langevin elements: a piezo stack clamped between a front and back mass, tuned to one frequency. Power is the rating of a single element — a plate or an immersible box carries several, and the total is set by the tank. Dimensions, stud thread and cable length are confirmed at quotation against the plate or vessel they are going into.

None of these is held in stock. Every element is supplied against a firm order, with the lead time advised at quotation. Dimensions, stud thread and cable length are set when the element is specified against the plate or vessel it is going into. Other frequencies and powers exist in each band and can be sourced the same way.

Need one element to run a coarse pass and a fine pass in the same tank? That is a dual-frequency element — 25/45, 28/68, 40/80, 40/130 and 80/130 kHz.

Replacing transducers in a tank you already own? Read this firstOpen

Elements are sold on their own. Building a plate, specifying an OEM machine, or wanting elements and nothing else is a normal order, and there is no requirement to buy a generator with them.

Re-elementing an array you already own is the case that needs care. When an immersible box or a bonded array has gone deaf, replace the whole block rather than the one element that failed. Transducers age together — output falls away, the resonant point drifts and the impedance climbs. Put one new element into an aged set and the drive cannot tune to both: it hunts, the new element takes more than its share of the power, and it fails early. Where the generator is the same age as the block it was tuned for, budget for both. Tell us what is in the tank now and roughly when it went in, and we will tell you which half actually needs replacing before you spend anything.

What has to line up →

Pairing

What drives them

BLT elements run on the multi-frequency VarioSonic G4 — the same generator that drives our immersible boxes. They do not run on the rod-resonator SonoDrive G5, and a rod does not run on a G4.

VarioSonic G4 multi-frequency ultrasonic generatorVarioSonic G4 generatorSingle or dual frequency · 800 to 1,500 WPick a model → Stainless immersible ultrasonic transducer boxImmersible transducersThe same elements, sealed into a box built to your tankSpecify a box →
How it is sold

Matching the drive to the array

A generator is tuned to the array it drives, not to a frequency on a label. What has to line up: the frequency the generator tracks, the total capacitance of the array wired to it, the impedance and phase that array presents once it is in the liquid, and the voltage across the group under load. Where we supply a complete system we specify those against each other and commission the two as one. Elements bought on their own are a different thing and a normal order — the matching is then yours or your builder’s to get right, and we will tell you what the elements need.

What goes wrong when they are not matched

The label is not the loadTwo transducers both marked 40 kHz are not the same electrical load — they differ in capacitance, in phase, and in how the assembly moves. A generator is tuned to a particular array, not to a number on a plate.
The tuning is inside the generatorA matching network — transformer ratio and a tuning inductance — cancels that array's capacitance so the drive sees a near-resistive load at resonance. Change the array and the power goes into heat and reactive current instead of cavitation.
Tracking only has a windowThe generator hunts for resonance within a narrow band around its design frequency. A stack outside that window is never found: the drive sits off resonance, runs hot, and trips or limits.
Power has to match both waysOverdriven, the ceramic depoles and the bond lines and the radiating face fail years early. Underdriven, there is no useful cavitation at all — a bath that looks like it is running and does not clean.
The cable counts tooCable capacitance sits inside the tuned circuit, which is why the length is quoted with the set and should not be extended on site.

A new generator will not rescue an old set. Transducers age — output falls away, the resonant point drifts and the impedance climbs — so an older array is no longer the load a new drive was tuned for. A set of mixed ages is worse again: the weakest element pulls the rest off tune and the drive spends its power hunting for a resonance that has moved. What you get is a generator running hot or dropping out, a bath cleaning unevenly, and transducers failing earlier than they should — and from the outside there is no way to tell which end is at fault, so you end up replacing both anyway.

What we can and cannot stand behind. Where we supply the generator and the transducers together, they are matched and commissioned as a system and warranted as one. Elements supplied on their own go onto a drive we have not characterised, so we cannot warrant what the tank will do with them. That is the limit of what we can know, not a refusal to sell. Tell us what the drive is and roughly when it went in, and we will say where you stand before you spend anything.

Enquire about BLT elements

Tell us the frequency and power you need, how many elements, and what they are going into — a plate you are building, an OEM machine, or a repair. If it is a repair, say what the tank is and how it failed.

Questions

BLT transducers, answered briefly

What is a BLT transducer?
BLT stands for bolt-clamped Langevin transducer. A stack of piezoelectric ceramic rings is clamped under high pre-load between a metal front mass and a back mass by a central bolt. Driving the stack with an alternating voltage makes the assembly expand and contract at its tuned frequency, and the front mass radiates that motion into whatever it is bonded to. It is the element inside every ultrasonic cleaning tank, immersible box and transducer plate.
What frequencies and powers do you supply?
20 kHz at 50 W or 100 W, 28 kHz at 100 W or 60 W, 40 kHz at 60 W, 68 kHz at 60 W, 80 kHz at 60 W and 130 kHz at 50 W. None of them is held in stock: every element is supplied against a firm order, with the lead time advised at quotation. Dimensions are set against the plate or vessel the element is going into. Dual-frequency elements are on their own page.
Can one element do two frequencies?
Yes. A dual-frequency element is built with two resonances rather than one, and the generator switches between them — a coarse note to break the deposit, a fine note to clear what it loosens, in the same tank off the same array. The pairings are 25/45 and 28/68 kHz at 50 W, and 40/80, 40/130 and 80/130 kHz at 60 W. Dual-frequency elements →
Can I buy transducer elements on their own?
Yes. Elements are sold on their own for building transducer plates, for OEM machines and for re-elementing a tank whose bonded array has gone deaf. You do not have to buy a generator with them. What we cannot do is warrant what a tank will do with elements fitted to a drive we have not characterised — the drive and the array have to suit each other, and we will tell you what the elements need.
How many transducers does my tank need?
It follows the tank volume, the soil and the duty, not a rule of thumb off the litres. Element count, spacing and bonding pattern are specified against the plate or the vessel. Send the tank dimensions and what you are cleaning and we will work it out.
Which frequency should I choose?
20 kHz for the heaviest work on robust steel. 28 kHz for scale, hard carbon and weld deposit. 40 kHz for general engineering and a better surface finish. 68 kHz for fine and precision work where the substrate will not take a heavy band. 80 kHz for fine particulate off plated and polished surfaces. 130 kHz for sub-micron particulate, optics and coated surfaces. Frequency follows the deposit and what the surface will tolerate, not the machine.
Can I replace a dead transducer on my existing tank?
Often, yes. A bonded array that has gone deaf can usually be re-elemented rather than the vessel scrapped. We need to know what is in there now, what generator drives it and roughly when it went in. If the generator is not ours, tell us what it is before you spend anything.
What is the difference between a transducer and an immersible?
The transducer is the element. An immersible is a sealed stainless box with several elements bonded to its inner face and a cable gland, built to hang in a tank you already own. A transducer plate is the same idea without the box, bonded directly to the vessel wall or base.
Do they come with a generator?
Only if you want one. Elements are quoted on their own. Where we supply a complete system the generator and the array are specified against each other and commissioned together, because the drive is tuned to the load the elements present. If you are driving them off something you already own, tell us what it is and we will tell you what the elements need.