BLT transducers — dual frequency
A dual-frequency element is one bolt-clamped Langevin transducer built with two resonances rather than one. The generator switches between them — a coarse note to break the deposit, a fine note to clear what it loosens — in the same tank, on the same parts, off the same array.
If the work is all one kind of soil on one kind of substrate, buy the right single frequency instead. Dual is for a tank that has to do two jobs.
Sold as elements — for building transducer plates, for OEM machines, and for re-elementing a tank whose bonded array has gone deaf. Quoted with the dual-frequency VarioSonic G4 that drives them.
Pairing by pairing
The first number does the work; the second does the finish. Choose the split by the deposit you are breaking and by what the surface will still tolerate on the second pass. No element is held in stock. Each pairing is supplied against a firm order, with the lead time advised at quotation. The power below is the rating of one element; a plate or box carries several. Dimensions are fixed at quotation, against the plate or vessel they are going into.
50 W · 25 / 45 kHzThe heaviest split. 25 kHz to break scale, hard carbon and weld deposit; 45 kHz to clear what it loosens without chewing the surface.Enquire →
50 W · 28 / 68 kHzWorkshop to finish in one tank — 28 kHz for the deposit, 68 kHz for the finish pass.Enquire →
60 W · 40 / 80 kHzGeneral engineering with a fine second pass. The pairing we are asked for most.Enquire →
60 W · 40 / 130 kHzThe widest useful split: general work at 40 kHz, sub-micron particulate at 130 kHz.Enquire →
60 W · 80 / 130 kHzBoth fine. For work that will not take 40 kHz at all — plated, polished and coated surfaces.Enquire →Element count, spacing and bonding are specified against the plate or the vessel. Dimensions and mounting detail are confirmed at quotation. Renders of the dual elements are being produced — the cards above are placeholders, not the part.
By pairing
| Part number | Pairing | Power | What it is for |
|---|---|---|---|
| MS300-25-45kHz-50W | 25/45 kHz | 50 W | Scale, hard carbon and weld deposit, then a clearing pass |
| MS300-28-68kHz-50W | 28/68 kHz | 50 W | Heavy deposit and a finish pass without moving the part |
| MS300-40-80kHz-60W | 40/80 kHz | 60 W | General engineering, then fine particulate off the surface |
| MS300-40-130kHz-60W | 40/130 kHz | 60 W | General work, then sub-micron particulate |
| MS300-80-130kHz-60W | 80/130 kHz | 60 W | Delicate and coated surfaces only, two levels of fine |
Each is a bolt-clamped Langevin element built with two resonances: a piezo stack clamped between a front and back mass, tuned so the assembly has a usable mode at each of the two frequencies. Power is the rating of a single element — a plate or an immersible box carries several, and the total is set by the tank.
We do not publish a power or a dimension against these until the element is specified. Dual elements are sourced against a firm order, and the generator is quoted with them — a dual element on a single-frequency drive only ever runs on one of its two notes.
One note only? The single-frequency elements run 20, 28, 40, 68, 80 and 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 drives them
Dual elements run on a dual-frequency VarioSonic G4 — the drive has to track two resonances and hold a recipe for each, which a single-frequency generator does not do. They do not run on the rod-resonator SonoDrive G5, and a rod does not run on a G4.
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
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 dual-frequency elements
Tell us the pairing you want, how many elements, and what they are going into — a plate you are building, an OEM machine, or a repair. If you are not sure of the pairing, tell us the deposit and the substrate and we will pick it.