The document presents a wireless pH-sensing tag for monitoring food quality. The tag includes a flexible pH sensor integrated with wireless communication circuitry, allowing for convenient and long-term in situ monitoring of food quality from production to retail without batteries. The proposed system connects a pH sensor to a microcontroller that receives sensor data and sends it via Zigbee to a PC for display. It would allow food producers and retailers to remotely monitor produce pH levels to ensure safety and reduce waste.

1. A Passive Radio-Frequency pH-Sensing Tag for
Wireless Food-Quality Monitoring
Abstract:
Here we are presenting a new method, suitable for food quality management by
wirelessly monitoring pH level changes in food with a flexible pH sensor which is embedded in a
battery less radio-frequency (RF) transponder. Conventional radar systems comprise a collocated
transmitter and receiver, which usually share a common antenna to transmit and receive. A
pulsed signal is transmitted and the time taken for the pulse to travel to the object and back
allows the range of the object to be determined. The wireless sensor tag includes a flexible pH
sensor based on miniature iridium oxide and silver chloride (AgCl) sensing electrodes integrated
on a deformable substrate, and battery less wireless communication circuitry. The sensor tag and
reader system is designed to achieve convenient, long-term, and on-demand wireless in situ
monitoring of food quality, especially for large-quantity applications and continuous monitoring
from place of production to retail stores.
Existing System:
In this existing system, there is device to monitor or to check the Ph rate of a food
material that can be used only in research labs. The existing method which not having the
wireless communication to transfer the data. So we go to our proposed system.
Proposed System:
In this project, we are going to pH sensor system that provides a direct and convenient
means to monitor produce/food quality to address food safety and waste issues. Here we connect
the pH sensor with microcontroller, which would receive the data signals from sensor for that we
have to place the sensor in the surface of the food material to sense the pH level. The status will
be sent through zigbee transceiver to the PC section which connected with the zigbee. The status
also been shown in LCD.

2. Block diagram:
Transmit Section:
Power
supply
PH sensor
8051
MICRO
CONTROLLER
LCD
Monitoring Section:
Power supply
Max232
PC

3. Hardware Requirements:





8051 Microcontroller and power supply
pH Sensor
LCD
Zigbee Transceiver
Max232
Software Requirements:
 Embedded C
 Keil compiler
Application:


The system can be used in food processing unit
The system can be used in homes and hotels
Advantages:


Low cost and Reliable
Easy to use