WEEK 8: 4TH MARCH 2012

Title : Do some research and explore more about the LM35DZ.

Objective : To study about the LM35DZ.

           

Contents / Procedure : Search about the LM35DZ principle and                                          its functions.

                  

Results / Analysis :

1)   The definition :

      LM35 is an integrated circuit sensor that can be used to measure temperature with an electrical output proportional to the temperature (in ^oC).

2)   The reasons why the LM35DZ will be use to measure temperature:

a)   It can measure temperature more accurately than a using a thermistor.

b)   The sensor circuitry is sealed and not subject to oxidation, etc.

c)   The LM35 generates a higher output voltage than thermocouples and may not require that the output voltage be amplified.

3)   The operation principle :

a)   It has an output voltage that is proportional to the Celsius temperature.

b)   The scale factor is .01V/^oC

c)   The LM35 does not require any external calibration or trimming and maintains an accuracy of  +/-0.4 ^oC at room temperature and +/- 0.8 ^oC over a range of 0 ^oC to +100^oC.

d)   Another important characteristic of the LM35DZ is that it draws only 60 micro amps from its supply and possesses a low self-heating capability. The sensor self-heating causes less than 0.1 ^oC temperature rise in still air.

4)   How to use the LM35DZ

a)   Need to use a voltmeter to sense Vout.

b)   The output voltage is converted to temperature by  a simple conversion factor.

c)   The sensor has a sensitivity of 10mV / ^oC.

d)   Use a conversion factor that is the reciprocal, that is 100 ^oC/V.

e)   The general equation used to convert output voltage to temperature is:

                                         i.    Temperature ( ^oC) = Vout * (100 ^oC/V)

                                        ii.    So if  Vout  is  1V , then, Temperature = 100 ^oC

                                       iii.    The output voltage varies linearly with temperature.

Conclusion: From the research, the LM35DZ can be used to                              measure the temperature for the Smart Chicken                              Coop.

WEEK 7: 29TH FEBRUARY 2012

Title : Do some research and explore more about the MaxSonar             Sensor.

Objective : To study about the MaxSonar Sensor.

           

Content / Procedure : Search about MaxSonar Sensor function                                          and operation principle.

                  

Results / Analysis :

The MaxSonar sensor

1)  The MaxSonar sensor is a range finders offers very short- to long-range detection and ranging in an incredibly small package with ultra-low power consumption.

2) It detects objects from certain range depends on its specification and provides sonar range information beyond certain range with a resolution.

3) The sensor provides three output interfaces, all of which are active simultaneously:

a)   digital pulse width output

b)   analog voltage output

c)   asynchronous serial digital output

Conclusion: From the research, the MaxSonar sensor can be                            used to indicate the level of the food when it is                                nearly empty.

WEEK 6 : 24TH FEBRUARY 2012

Title : Do some research and explore more about the Water                   Level Sensor.

Objective : To study about the Water Level Sensor.

           

Contents / Procedures : Search about the Water Level                                                            Sensor principle and its applications.

                  

Results / Analysis : 

1) The principle

     A low AC voltage is applied between the probe electrode and      the tank wall (or reference electrode in case of insulated tank).      When the water/liquid comes in contact with the electrode tip,        a conductive path is established between the sense electrode      and the tank wall/reference electrode. This current is sensed,        amplified and made to operate a relay whose contacts in turn        can be used for annunciation/control.

2) Applications

    The Water Level Sensor is to maintain a constant water level         avoiding material wastage in your process plant. Common             applications also include switching pumps on and off to avoid       overflow, dry running and indicating water level in an empty           tank to avoid wear and tear and production stoppage.

Conclusion: From the research, the Water Level Sensor, can be                        use to indicate the level of the water when                                        it is nearly empty.