Convolution / Fin Counter

The CFC-201 is the latest in a series of instruments designed by Jodon to meet the ever-increasing demands for product quality by the heat exchanger industry. It has been designed to greatly increase the accuracy of performing tedious specification confirmation counts, while spending a fraction of the time in the process.

The CFC-201 Convolution/Fin Counter is a hand-held, battery-powered instrument used for precisely counting long columns of louvered convolutions or cooling fins. The fully digital counter has the capacity of counting up to 9,999 convolutions or fins. Typically a conventional automobile radiator will incorporate as many as 180 to 350 convolutions. By definition, there will be twice as many fin panels in the same column. The number of convolutions in a conventional automotive heater, air conditioner evaporator, or charge air cooler will be significantly less. The ability of the CFC-201 to count many times the expected count requirement should cover virtually all contingencies.


The new instrument includes a digital display of the count with a measurement accuracy of one-half of one percent (±0.5%, ±1 count), resolved to the nearest whole count. The displayed digital count will hold until the operator resets the instrument. An automatic circuit shutoff is provided to conserve battery power, should the counter remain inactive for 3 minutes. Under normal operation, the counter will provide 1 to 2 weeks of intermittent use using a standard 9-volt battery. The instrument weighs 6 ounces (170 gm), including the battery.


The Model CFC-201 includes the instrument, a recharging module (CFC-C9) , and operating instructions.


As the operator draws the counter stylus perpendicularly across the convoluted (or finned) surface, a dynamic standing wave is induced into the stylus arm. An integrated circuit containing a sensitive microphone is mounted to the stylus arm inside the sealed enclosure. The induced standing wave causes the accelerometer to produce an electrical output which represents the motion of the stylus tip. After appropriate electrical filtering and pulse shaping, the signal is acted upon by a count circuit to produce a summation of pulses representing the number of convolutions/fins over which the stylus has been drawn. That number of pulses is then displayed on the 6-digit LCD display.


Simply turn the unit on and draw the stylus across the sample to be counted. A little practice may be necessary to determine the optimum scan speed, and incident angle between the plane of the sample and the longitudinal axis of the stylus. Typically, an angle of about 45 degrees works best. Be sure to start at the first convolution/fin, and hold the angle steady through the very last convolution/fin. Read and take note of the count.

Optional Battery Charging System Model CFC-C9

A separate Nickel-Metal hydride (Ni-MH) battery charger is available for use in recharging the internal battery without removing the battery from the instrument. the Model CFC-C9 charger simply plugs into the chassis mounted electrical receptacle on the CFC-201 instrument. Charging is also available for use with 220VAC, 50 Hz electrical service.

The charger will fully charge the internal Ni-Metal hydride battery in five (5) hours or less. The charger includes overcharge protection circuitry to prevent damage to the battery or the charger, should the charger be left connected beyond the normal charging period.


Replacement of the internal Ni-MH battery (9V) can be installed by the customer using simple hand tools. The battery actually clips into place after the instrument case has been parted. All other instrument repairs, including the servicing of the LCD display, should be referred to the Jodon Service Department.


The CFC-201 is warranted to be free of material and workmanship defects, or subspecification performance for a period of 90 days from the date of purchase.