湿度传感器挑选的注意事项
①.挑选丈量规模和丈量分量、温度一样,挑选湿度传感器首先要断定丈量规模。除了气候、科研部门外,搞温、湿度测控的一般不需求全湿程(0-100%RH)丈量。
②、挑选丈量精度丈量精度是湿度传感器最重要的目标,每提高个百分点,对湿度传感器来说就是上一个台阶,乃至是上一个档次。因为要到达不同的精度,其制造本钱相差很大,售价也相差甚远。所以运用者一定要因地制宜,不宜盲目寻求高、精、尖。如在不同温度下运用湿度传感器,其示值还要考虑温度漂移的影响。众所周知,相对湿度是温度的函数,温度严重地影响着指定空间内的相对湿度。温度每改变0.1℃。将发生0.5%RH的湿度改变(差错)。运用场合如果难以做到恒温,则提出过高的测湿精度是不合适的。大都情况下,如果没有准确的控温手法,或许被测空间对错密封的,5%RH的精度就足够了。关于要求准确操控恒温、恒湿的部分空间,或许需求随时盯梢记录湿度改变的场合,再选用3%RH以上精度的湿度传感器。而精度高于2%RH的要求恐怕连校准传感器的规范湿度发生器也难以做到,更何况传感器自身了。相对湿度丈量外表,即使在2025℃下,要到达2%RH的准确度仍是很困难的。一般产品资料中给出的特性是在常温(20℃10℃)和洁净的气体中丈量的。
③、考虑时漂和温漂在实际运用中,因为尘土、油污及有害气体的影响,运用时间一长,电子式湿度传器会发生老化,精度下降,电子式湿度传器年漂移量一般都在2%左右,乃至更高。一般情况下,生产厂商会标明1次标定的有用运用时间为1年或2年,到期需从头标定。
④、其它注意事项湿度传感器对错密封性的,为保护丈量的准确度和稳定性,应尽量防止在酸性、碱性及含有机溶剂的气氛中运用。也防止在粉尘较大的环境中运用。为正确反映欲测空间的湿度,还应防止将传感器安放在离墙面太近或空气不流通的死角处。如果被测的房间太大,就应放置多个传感器。有的湿度传感器对供电电源要求比较高,否则将影响丈量精度。或许传感器之间彼此干扰,乃至无法作业。运用时应按照技能要求供给合适的、契合精度要求的供电电源。传感器需求进行远间隔信号传输时,要注意信号的衰减问题。当传输间隔超过200m以上时,主张选用频率输出信号的湿度传感器。
Points for attention of humidity sensor selection
Select the measurement scale and measurement components, temperature, select the humidity sensor, first determine the measurement scale. In addition to climate, scientific research department, the temperature and humidity measurement and control generally do not require total wet range (0-100%RH) measurement.
Selecting the measuring accuracy and measuring accuracy is the most important target of humidity sensor. Every increase of percentage point is the last step of the humidity sensor, even the last grade. Because of the different precision, the manufacturing cost is very different, and the price is also very different. Therefore, the operator must adjust measures to local conditions, should not blindly seek high, fine, sharp. If the humidity sensor is applied at different temperatures, the indication value should also consider the influence of temperature drift. As is known to all, relative humidity is a function of temperature, and temperature seriously affects the relative humidity in a given space. The temperature varies by 0.1 degrees centigrade. The humidity changes of 0.5%RH will occur (Cha Cuo). If it is difficult to use constant temperature, it is unsuitable to put forward too high humidity measuring accuracy. In most cases, if there is no accurate temperature control technique, or the measured space to the wrong seal, the accuracy of 5%RH is enough. For the accurate control of constant temperature and humidity of the space, may at any time change record demand shadowed humidity occasions, then use 3%RH above humidity sensor accuracy. And the accuracy is higher than the 2%RH requirements, I am afraid even calibration sensor standard humidity generator is difficult to do, not to mention the sensor itself. The accuracy of relative humidity measurement is still difficult to reach 2%RH even at 2025 degrees centigrade. The characteristics of the general product data are measured at room temperature (20 C, 10 C) and clean gas.
Considering the influence of dust, oil pollution and harmful gas, the electronic humidity transmitter will be aged and the accuracy will be decreased. The annual drift of electronic humidity transducer is generally around 2%, even higher. In general, manufacturers will indicate that the useful time of the 1 calibration is 1 years or 2 years, and the expiration date needs to be calibrated from scratch.
Fourth, other precautions, the humidity sensor for the error tightness, for the protection of measurement accuracy and stability, should try to prevent the use of acidic, alkaline and containing solvent atmosphere. Also prevent the use of dust in the larger environment. In order to correctly reflect the humidity of the space to be measured, the sensor should be prevented from being placed too close to the wall or the dead corner of the air. If the room is too large, multiple sensors should be placed. Some humidity sensors on the power supply requirements are relatively high, otherwise it will affect the measurement accuracy. Maybe the sensors interfere with each other and can't even work. The power supply should be supplied according to the technical requirements in accordance with the technical requirements. The signal attenuation problem should be paid attention to when the sensor needs to transmit the signals in long distance. When the transmission interval is more than 200m, the humidity sensor is recommended to select the frequency output signal.
本网站关键词专注于温湿度变送器 、温湿度传感器、温湿度记录仪、水浸传感器 、断电报警器
本文地址:http://www.sdrkck.com/news/hangye/397.html,欢迎转载。