Diagnosing ultrasonic scaler output power
How output power is controlled
In case of decreased USS power output, the issue can be with:
- the control panel module
- the USS module
- the USS hose
- the USS handpiece
- the USS handpiece tip
- poor wiring/contact
From the above, one can see, that EMS FS-367 uses 0-5V control of the module. EMS FS-433 and FS-432 don’t say what this value is, but one can see, that the Uref line (the one which controls the scaler module output power) is connected to TB_PREM, connector X10, pin 2. It is the same pin, where FS-367 is connected, which has 0-5V control, so logically, FS-433 and FS-432 will also have 0-5V control.
Looking at the TB_PREM wiring diagram below, one can see, that connector X10 is used for connection to scaler module. One can also see, that there are 2 pins to control the scaler output power. Pin 1 sends out 0-10V and pin 2 sends out 0-5V.
The scaler module’s Uref line is always connected to one of the 2 pins, depending on the control required by the scaler module manufacturer. Some electronics (like the ECO electronics) can have only one pin on the control panel module to control the scaler output power, then there is a mechanism to select what control it is, like a switch, jumper or connector option.
Diagnosing the output power
To diagnose the output power, one can see if the control panel module gives correct voltage to the scaler module.
In order to check this, one needs to set 100% output power for the scaler on the control panel and then check the voltage on the Uref line (i.e. between GND and Uref wires, namely black and pink wires in our EMS FS-432 example).
If the scaler requires 0-5V control, then with 100% foot controller activation, one needs to read 5V on the Uref line. This value decreases proportionally, depending on the foot control activation. This is the voltage sent to the scaler module. If the voltage on the Uref line is correct, the issue may be in the scaler module, hose or handpiece. Unfortunately, without an oscilloscope, one has no option to find out where exactly the problem lies within the scaler module, hose or handpiece.
If the voltage on Uref line is not correct, then the control panel module is faulty.
Possible issues
In case of correct Ureg line voltage but poor performance of the scaler, there might be one of the following issue:
- scaler module – might be damaged if not used in accordance with manufacturers conditions/limitations
- scaler hose – might get poor connection on one (or both) of the ends, wiring inside might be broken
- scaler handpiece – contains a small crystal, which vibrates to create the tip vibrations. If the handpiece drops to the floor, gets hit against some hard surface, or otherwise abused, the crystal can get misaligned or broken, causing low output power.
- scaler tip – if non-original (manufacturer made) part is used, the performance can be drastically different. The tip state is also an important factor. Used tip which is 1mm shorter to it’s original lenght has around 25% lower performance. Used tip shorter by 2mm can have perfromance dropped by 50%.
- wiring between the control panel module and the scaler module is loose