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Common Inquiries

HOW IS ULTRASOUND GENERATED?
Ultrasound is generated by applying an alternating voltage to a synthetic crystal in order to produce
high‐frequency sound waves.  The crystals, typically made of lead zirconate titanate, expand and
contract one million times each second for 1‐MHz output and three million times per second for 3‐MHz.  
Power/intensity is controlled by altering the voltage of the signal applied to the crystal.
HOW DO I KNOW IF MY ULTRASOUND IS WORKING?
If there are questions regarding the operation of your ultrasound applicator, a simple test can verify the
presence (or absence) of ultrasound. Sprinkle a few drops of water onto the surface of the ultrasound
transducer (the part that contacts the patient) and slowly increase the ultrasound output. If ultrasound
is present, the water droplets will cavitate or “dance around” the surface of the transducer. CAUTION:
This test confirms ultrasound function, but does not confirm calibration. Contact Kowalski Calibration to
schedule a calibration service if you have concerns about the safe and effective operation of you
ultrasound.
WHAT IS ULTRASOUND CALIBRATION?
Ultrasound calibration can only occur if the output is measured using a high‐precision ultrasound watt
meter. The output is sampled at various levels and compared to the machine’s output meter indication.  
If the difference between the meter indication and the actual measured output is within ±20% (industry
standard), the device is operating satisfactorily. Kowalski Calibration endeavors to provide a ±10%
tolerance on adjustable ultrasound devices (note: not all models allow for service adjustment). We have
found that by adhering to a ±10% tolerance, the natural changes that take place to the physical properties of the crystal are less likely to create dangerous out‐of‐tolerance conditions over the course of the following year.  Other devices requiring annual calibration are traction units and hand testing instruments.
WHY IS IT NECESSARY TO HAVE MY ULTRASOUND CALIBRATED ANNUALLY?
There are two important aspects to an ultrasound calibration:  
1. Tuning.  Each ultrasound transducer (crystal) reacts to a specific, unique frequency.  When a sine
wave of this frequency is applied, the crystal operates in a most efficient manner (highest
performance with minimal effort).   The tuning process alters the applied sine wave frequency in
order to match the physical properties of the crystal.   
2. Output power adjustment.  Adjustments made during the calibration process to match the
measured output and the indicated output.
The physical properties of the synthetic crystals used to generate ultrasound change over time.  The rate
of change is highest early in the crystal’s life and lesser as the crystal ages.  Because of this
characteristic, manufacturers will allow new crystals to age for a year or more before using them in their
new ultrasound heads.
As time passes and crystals experience these subtle changes, their specific, unique frequency
requirements change and they are no longer operating efficiently.  Kowalski Calibration monitors
ultrasound performance annually and makes the necessary tuning and power adjustments to keep the
crystals operating at their maximum potential.
AM I REQUIRED TO HAVE MY EQUIPMENT CALIBRATED?
Whether or not one is required to have it done, responsible clinicians ensure their equipment is
operating safely and effectively for the benefit of their patients.  Manufacturers recommend annual
calibration for the reasons detailed in the “WHY IS IT NECESSARY TO HAVE MY ULTRASOUND
CALIBRATED?” section.  Governing bodies may also have regulations that apply to you.  For example,
annual calibration is required for measuring instruments used at facilities accepting Medicare (42 CFR
410.33).  And, the Commission on Accreditation of Athletic Training Education (CAATE) requires annual
calibration for ATP lab equipment as well as for the equipment at their preceptor sites.  There is also the
issue of liability which rests solely on the principal(s) of the facility should they choose to forego regular equipment safety and calibration services.
WHAT DOES THE KOWALSKI CALIBRATION STICKER REPRESENT?
The Kowalski Calibration CERTIFIED DEVICE sticker is more than just a date sticker.  It represents a 26+
year dedication to maintaining safe and effective equipment.  It represents an understanding of our role
in the patient care circle, a role we accept and take very seriously.  All devices displaying our sticker have
been thoroughly tested and are operating as originally designed.  Coupled with our detailed CLINICAL
SAFETY REPORT AND CERTIFICATE OF CALIBRATION, clinicians have no doubt as to the efficacy of their
modalities.
WHY DOES MY HOT PACK UNIT KEEP SHUTTING OFF?
Some Chattanooga and Whitehall hot pack heating units use over‐temperature sensors to safeguard
against a thermostat failure.  The operational thermostat is set to maintain a temperature between 160°
– 167°F, while the over‐temperature sensor is designed to trip around 190°F.  In the event the
operational thermostat fails, the heating element will either not turn on or worse, not turn off.  The
former results in room temperature water, while the latter results in boiling water leading to
evaporation and eventual heating element destruction.  The over‐temperature sensor prevents the
water from boiling in the event of an operational thermostat failure.  
There are times, however, when the over‐temperature sensor itself fails by tripping at a lower
temperature.  To recognize the water temperature at the time the over‐temperature sensor trips is
helpful to pinpoint which of the thermostats is failing.
WHY DO MY HOT PACKS KEEP BURSTING?
Many clinicians believe this condition is caused by water that is too hot, when in actuality the opposite is true.  Hot packs can develop bacteria when water temperatures not maintained at a minimum of 160°F.   This bacteria causes the hot packs to weaken and split open.  Replacing damaged packs without addressing the issue keeps the cycle going indefinitely, as new packs are immediately infected.  To resolve the problem:
 1. Throw away all hot packs that have been in contact with the water.
2. Clean the hot pack heating unit thoroughly using a solution of 1 part white vinegar and 3 parts water.
3. Fill the hot pack heater with clean water and ensure temperature range of 160° – 167°F.
4. Install new hot packs.
5. Change the water and clean the hot pack unit regularly (refer to operator’s manual) to ensure a clean environment for your hot packs, clinicians and patients.
MY FLUIDOTHERAPY UNIT IS RUNNING, BUT THE MEDIA IS BARELY MOVING. WHY?
The model 115 uses a dual‐blower air system.  Over time, these blowers will fail and require replacement.  Even though the blowers are the same age, they will fail at different times.  When the first blower fails, the second blower continues to operate and produce some fluidization.  However, the air pressure is reduced by much of the air escaping through the malfunctioning blower, resulting in reduced fluidization.  The clinician will hear the blower and assume the Fluidotherapy unit is functioning normally, but increasing blower speed does not increase fluidization.  Because the still‐ functioning blower will also fail soon, Kowalski Calibration replaces blowers in pairs.

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