|Life term||1 year||10-12 months||2 years||1 year|
|Humidity Accuracy||+/- 2%||+/- 3%||+/- 1,8%||+/- 3.5%|
|Humidity Range||0 – 100%||0 – 100%||0 – 100%||0 – 100%|
|Temperature Range||-40 – + 125 °C||-40 – +125°C||-40 – +125°C||-40°C – +85°C|
|Response Time||8 sec (2-wire interface)||8 sec (tau 63%)||8 sec (tau 63%)||15 sec|
In the technological industry, humidity is defined as “the water vapor content in air or other gases” (Wilson 271). Humidity has to be measured in terms of, for example, absolute humidity and relative humidity. One of the possible ways to measure any kind of humidity is to develop appropriate humidity sensors which may be differentiated by their costs or some other features (McDowall 130). In this paper, four different types of humidity sensors will be compared: SHT71, SHT75, SHT15, and HIH-4000-001 by HONEYWELL S&G (Eady 275; Huang 621).
One of the first characteristics to be compares is based on humidity sensors’ expiration dates. In fact, the sensors chosen for the analysis have almost the similar indicators, and may serve around 1 year. However, in this category, the humidity sensor SHT75 takes the leading position. Its expiration date is about 2 years or even more depending on the conditions of its exploitation. Considering this fact, it is also necessary to admit that its price is the highest in comparison to other sensors and the actual sensor under consideration. SHT15 and SHT71 humidity sensors have the same price that is $30.24, and the price of SHT75 is $35.18.
The difference is not significant, still, the qualities of the most expensive product deserve much attention, In comparison to the actual sensor that is developed to meet a number of demanding measurements (SHT15 – Digital Humidity Sensor), SHT75 humidity sensor deals with high-precision measurements (SHT75 – Digital Humidity Sensor). However, there is one more factor that differentiates the sensors under analysis and makes the customers focus more on SHT75 model. It is humidity accuracy. The lowest rate are obtained by SHT75 sensor (1,8%); and other sensors demonstrate different percentage of accuracy from 2 to 3,5% (SHT71 – Digital Humidity Sensor).
Among the chosen humidity sensors, the most unsafe data is offered by HIH-4000-001 humidity sensor. Probably because of this point, its price is the lowest ($18.89). This model also differ in many other characteristics: its response time is the longest, 15 seconds (HONEYWELL S&G – HIH-4000-001), and it may work under the temperature that varies from -40 to +85°C. The rest of the sensors may be used under the temperature between -40 to +125°C. Finally, humidity range is similar for all sensors; in fact this point is usually similar for all sensors should correspond to the set operational values.
In general, after four different humidity sensors have been analyzed, it is possible to define the one model that is the most powerful and better from the vast majority of perspectives. In spite of the fact that the price of SHT75 humidity sensor is the highest, its characteristics are the most appropriate for different users. Very often, it is better to pay more but be confident in services and quality offered. This is why in comparison to the actual sensor given, SHT75 humidity sensor seems to be more preferable and more reliable to make use of.
Eady, Fred. Hands-on ZigBee: Implementing 802.15.4. with Microcontrollers. Jordan Hill, Oxford: Elsevier Inc., 2007. Print.
“HONEYWELL S&G – HIH-4000-001.” Newark. 2010. Web.
Huang, Han-Way. The HCS12 / 9S12: An Introduction to Software and Hardware Interfacing. Clifton Park, NY: Delmar, 2010. Print.
McDowall, Robert. Fundamentals of HVAC Control Systems. Atlanta, GA: Elsevier Science, 2009. Print.
“SHT15 – Digital Humidity Sensor.” Sensirion: The Sensor Company. n.d. Web.
“SHT71 – Digital Humidity Sensor.” Sensirion: The Sensor Company. n.d. Web.
“SHT75 – Digital Humidity Sensor.” Sensirion: The Sensor Company. n.d. Web.
Wilson, Jon, S. Sensor Technology Handbook, Vol.1. Jordan Hill, Oxford: Elsevier, 2005. Print.