A handy and accurate device to measure smallest diameter of log to reduce measurement errors

Log is a forest product as a basic ingredient of furniture such as cabinets, chairs, and other refined products. It is widely used by all people as households, offices, and shops. Thus, business in log industry is promising. Yet, a problem in pricing of log is faced by log business industry. Traditional pricing method is generally based on the calculation of log content (volume) where the value begins with the diameter measurement. Workers measure the smallest diameter value of log to be used as a reference. Conventionally, calculation begins with adding the horizontal and vertical diameters; the result is then divided by two. Error in measuring a log diameter occurs since it does not always form a perfect circle. Besides, measurements taken by one person to another will vary. In fact, a small difference of just one centimeter can determine the log grade which impacts on the price and economic loss of the industry. In this paper, a handy but accurate device is proposed that can be used in standardizing the measurement of log. The device is designed with raspberry pi as single board circuit embedded with image processing technology. The device is equipped with SD card to be easily replicable for mass production, and it has only 500 gram weight and dimensions of 90 × 55 × 60 mm. The measurement tests of real log with grade 17, 18, and 19 result 0.4%-1.9% and 0.08%-3.4% for minimal and maximal errors respectively. The proposed tool exhibits its accuracy, and it also effectively reduce the time measurement twice compared to conventional way.