Fish Freshness Detector Design

The article describes a method for determining fish freshness. The freshness detector is composed of trimethylamine (TMA) sensor, AT89C2051, AT89C4051 single chip and EDM12816B LCD module.The edibleness will decrease with the lowing of the fish freshness after the death of fish. So, freshness is a very important indication of the fish edibleness. By the recent research, it' s found that TMA vapor is produced when the fish is being stored and its concentration increases with the lowing of the fish freshness. So, TMA vapor is very suitable to measure fish freshness with no damage and field applications. The detector designed by us uses the TMA sensor made by our own school and the AT89C2051 single chip to design the circuit that can convert the concentration signal into the electronic signal. And the AT89C4051 single chip can measure the frequency of the electronic signal and judge the grade of fish freshness. At last, the freshness result will be displayed on the LCD.The operation and result observing of the fish freshness are very convenient. The detector can measure the concentration of the TMA vapor between 0 and 0. 2 %o. The detector can provide the consumers credible fish freshness information. And the result the fish freshness can be divided into two grades.