Pt100:核心细节一览

温度测量

Pt100 在工业液体、气体及固体的温度测量中扮演着重要角色,并且拥有多种不同的版本。欢迎进一步了解这款智能温度传感器的结构设计及其工作特性!
Table of content

What is a Pt100?

Pt100 是工业温度计中最常用的感温元件,其欧姆电阻会随温度的变化而改变。当它与评估单元(或测量仪表)相连时,即可通过测得的电阻值来确定当前的温度。Pt100 通常也被称为 Pt100 传感器或电阻传感器。

How is a Pt100 constructed?

Pt100 通常以铂芯片温度传感器的形式使用,它由一个陶瓷载体构成,表面通过溅射工艺覆盖了一层极薄的铂层。由于这层铂层非常薄,因此这类传感器通常被称为‘薄膜传感器’。随后,利用光刻工艺将这层铂涂层加工成蜿蜒曲折的蛇形图案。连接导线被焊接在焊盘上,这些接触面会使用一层玻璃进行应力消除(缓冲保护)。此外,还有一层经过熔融处理的玻璃层作为覆盖层,用于保护铂金属蛇形走线免受外部环境影响,并起到绝缘作用。

image
https://do2p1q9b92sgp.cloudfront.net/rendition/353604884319/image_uka2c4j8hp3ad9qmlg0v6cnp0v/
Structure of a Pt100 sensor
核心感温元件
m
portrait
image
https://do2p1q9b92sgp.cloudfront.net/rendition/353604884319/image_0rf4jn15up531cji99r8pgad37/
Size comparison of a Pt100 sensor
Pt100 传感器尺寸对比
m
landscape

Where is a Pt100 with connection wires used?

带引线的 Pt100 主要用于工业电气温度测量中的 RTD(热电阻)温度探头。

此外,薄膜传感器还提供表面贴装器件(简称 SMD)设计。这种传感器没有任何导线连接,而是通过可焊接的连接帽,直接焊接在电路板上。
image
https://do2p1q9b92sgp.cloudfront.net/rendition/353604884319/image_stnj1ngl4p1rd3tab9psg4445j/
Structure of a Pt100 sensor in SMD design
SMD(表面贴装)设计 Pt100 传感器的结构
m
portrait
image
https://do2p1q9b92sgp.cloudfront.net/rendition/353604884319/image_dktd3g8is16oj3cdnjd9deki19/
Size comparison of a Pt100 sensor in SMD design
SMD(表面贴装)设计 Pt100 传感器的尺寸对比
m
landscape

Where is a Pt100 in SMD design type used?

SMD(表面贴装)设计的 Pt100 传感器非常适合用于电路板表面或环境温度的测量,是温度监控或补偿电路的首选。此外,SMD 传感器的另一个热门用途是用于制造温度探头的测量插芯。通过将 SMD 设计的 Pt100 传感器自动化地贴装到电路板上,可以制成预组装的测量插芯,然后将其直接插入保护套管(Thermowell)中。例如,这类探头被大量应用于热量计量(热值测量)领域。

What is a wirewound Pt100?

铂芯片温度传感器自 20 世纪 80 年代问世以来,在很大程度上取代了此前一直使用的铂丝绕线式 Pt100 传感器。这些绕线式传感器的铂丝绕组,要么被熔封在玻璃中(玻璃传感器),要么被安置在陶瓷管的孔洞中(陶瓷传感器)。

image
https://do2p1q9b92sgp.cloudfront.net/rendition/353604884319/image_qccd5po99p6mraa95el7qhb125/
Structure of a glass sensor
玻璃传感器的结构
m
portrait
image
https://do2p1q9b92sgp.cloudfront.net/rendition/353604884319/image_m75so3o3256mh4lvdij2s6hv1s/
Structure of a ceramic sensor
玻璃传感器的结构
m
landscape

Where are wirewound Pt100 sensors used?

使用这些传感器(玻璃传感器)最高可进行 800°C 的测量。在特殊应用中(例如实验室),绕线式传感器至今仍被使用。不过,通常还是使用上文所述的铂芯片温度传感器(薄膜传感器)。

What does Pt100 stand for?

“Pt”是铂(Platinum)的化学代号,数字 100 代表其在 0°C 时的基础电阻值为 100 欧姆。

How does a Pt100 work?

在 0°C 时,Pt100 的基础电阻为 100 欧姆。随着温度升高,该传感器的电阻变化率约为 0.38 欧姆/开尔文(即温度每变化 1°C,电阻改变 0.38 欧姆)。其特性曲线遵循标准化规范(DIN EN 60751),因此评估单元可以直接根据测得的电阻值来确定传感器的温度。

如需了解 Pt100 传感器在电子温度计中应用的更多信息,请观看相关视频。

What is a Pt100 resistance table?

上述 Pt100 的特性可以很方便地从 Pt100 电阻表中读取。

以下是 Pt100 以 1°C 为步进的电阻参考值:

"<table class=\"table jumo-table\"><colgroup><col><col><col><col><col><col><col><col><col><col><col></colgroup><tbody><tr dir=\"ltr\"><th dir=\"ltr\" ><p class=\"\" dir=\"ltr\"><span >°C</span></p></th><th ><p class=\"\"><span >0</span></p></th><th ><p class=\"\"><span >1</span></p></th><th ><p class=\"\"><span >2</span></p></th><th ><p class=\"\"><span >3</span></p></th><th ><p class=\"\"><span >4</span></p></th><th ><p class=\"\"><span >5</span></p></th><th ><p class=\"\"><span >6</span></p></th><th ><p class=\"\"><span >7</span></p></th><th ><p class=\"\"><span >8</span></p></th><th ><p class=\"\"><span >9</span></p></th></tr><tr><td ><p class=\"\"><span >0</span></p></td><td ><p class=\"\"><span >100.000</span></p></td><td ><p class=\"\"><span >100.391</span></p></td><td ><p class=\"\"><span >100.781</span></p></td><td ><p class=\"\"><span >101.172</span></p></td><td ><p class=\"\"><span >101.562</span></p></td><td ><p class=\"\"><span >101.953</span></p></td><td ><p class=\"\"><span >102.343</span></p></td><td ><p class=\"\"><span >102.733</span></p></td><td ><p class=\"\"><span >103.123</span></p></td><td ><p class=\"\"><span >103.513</span></p></td></tr><tr><td ><p class=\"\"><span >10</span></p></td><td ><p class=\"\"><span >103.903</span></p></td><td ><p class=\"\"><span >104.292</span></p></td><td ><p class=\"\"><span >104.682</span></p></td><td ><p class=\"\"><span >105.071</span></p></td><td ><p class=\"\"><span >105.460</span></p></td><td ><p class=\"\"><span >105.849</span></p></td><td ><p class=\"\"><span >106.238</span></p></td><td ><p class=\"\"><span >106.627</span></p></td><td ><p class=\"\"><span >107.016</span></p></td><td ><p class=\"\"><span >107.405</span></p></td></tr><tr><td ><p class=\"\"><span >20</span></p></td><td ><p class=\"\"><span >107.794</span></p></td><td ><p class=\"\"><span >108.182</span></p></td><td ><p class=\"\"><span >108.570</span></p></td><td ><p class=\"\"><span >108.959</span></p></td><td ><p class=\"\"><span >109.347</span></p></td><td ><p class=\"\"><span >109.735</span></p></td><td ><p class=\"\"><span >110.123</span></p></td><td ><p class=\"\"><span >110.510</span></p></td><td ><p class=\"\"><span >110.898</span></p></td><td ><p class=\"\"><span >111.286</span></p></td></tr><tr><td ><p class=\"\"><span >30</span></p></td><td ><p class=\"\"><span >111.673</span></p></td><td ><p class=\"\"><span >112.060</span></p></td><td ><p class=\"\"><span >112.447</span></p></td><td ><p class=\"\"><span >112.835</span></p></td><td ><p class=\"\"><span >113.221</span></p></td><td ><p class=\"\"><span >113.608</span></p></td><td ><p class=\"\"><span >113.995</span></p></td><td ><p class=\"\"><span >114.382</span></p></td><td ><p class=\"\"><span >114.768</span></p></td><td ><p class=\"\"><span >115.155</span></p></td></tr><tr><td ><p class=\"\"><span >40</span></p></td><td ><p class=\"\"><span >115.541</span></p></td><td ><p class=\"\"><span >115.927</span></p></td><td ><p class=\"\"><span >116.313</span></p></td><td ><p class=\"\"><span >116.699</span></p></td><td ><p class=\"\"><span >117.085</span></p></td><td ><p class=\"\"><span >117.470</span></p></td><td ><p class=\"\"><span >1178.56</span></p></td><td ><p class=\"\"><span >118.241</span></p></td><td ><p class=\"\"><span >118.627</span></p></td><td ><p class=\"\"><span >119.012</span></p></td></tr><tr><td ><p class=\"\"><span >50</span></p></td><td ><p class=\"\"><span >119.397</span></p></td><td ><p class=\"\"><span >119.782</span></p></td><td ><p class=\"\"><span >120.167</span></p></td><td ><p class=\"\"><span >120.552</span></p></td><td ><p class=\"\"><span >120.936</span></p></td><td ><p class=\"\"><span >121.321</span></p></td><td ><p class=\"\"><span >121.705</span></p></td><td ><p class=\"\"><span >122.090</span></p></td><td ><p class=\"\"><span >122.474</span></p></td><td ><p class=\"\"><span >122.858</span></p></td></tr><tr><td ><p class=\"\"><span >60</span></p></td><td ><p class=\"\"><span >123.242</span></p></td><td ><p class=\"\"><span >123.626</span></p></td><td ><p class=\"\"><span >124.009</span></p></td><td ><p class=\"\"><span >124.393</span></p></td><td ><p class=\"\"><span >124.777</span></p></td><td ><p class=\"\"><span >125.160</span></p></td><td ><p class=\"\"><span >125.543</span></p></td><td ><p class=\"\"><span >125.926</span></p></td><td ><p class=\"\"><span >126.309</span></p></td><td ><p class=\"\"><span >126.692</span></p></td></tr><tr><td ><p class=\"\"><span >70</span></p></td><td ><p class=\"\"><span >127.075</span></p></td><td ><p class=\"\"><span >127.458</span></p></td><td ><p class=\"\"><span >127.840</span></p></td><td ><p class=\"\"><span >128.223</span></p></td><td ><p class=\"\"><span >128.605</span></p></td><td ><p class=\"\"><span >128.987</span></p></td><td ><p class=\"\"><span >129.370</span></p></td><td ><p class=\"\"><span >129.752</span></p></td><td ><p class=\"\"><span >130.133</span></p></td><td ><p class=\"\"><span >130.515</span></p></td></tr><tr><td ><p class=\"\"><span >80</span></p></td><td ><p class=\"\"><span >130.897</span></p></td><td ><p class=\"\"><span >131.278</span></p></td><td ><p class=\"\"><span >131.660</span></p></td><td ><p class=\"\"><span >132.041</span></p></td><td ><p class=\"\"><span >132.422</span></p></td><td ><p class=\"\"><span >132.803</span></p></td><td ><p class=\"\"><span >133.184</span></p></td><td ><p class=\"\"><span >133.565</span></p></td><td ><p class=\"\"><span >133.946</span></p></td><td ><p class=\"\"><span >134.326</span></p></td></tr><tr><td ><p class=\"\"><span >90</span></p></td><td ><p class=\"\"><span >134.707</span></p></td><td ><p class=\"\"><span >135.087</span></p></td><td ><p class=\"\"><span >135.468</span></p></td><td ><p class=\"\"><span >135.848</span></p></td><td ><p class=\"\"><span >136.228</span></p></td><td ><p class=\"\"><span >136.608</span></p></td><td ><p class=\"\"><span >136.987</span></p></td><td ><p class=\"\"><span >137.367</span></p></td><td ><p class=\"\"><span >137.747</span></p></td><td ><p class=\"\"><span >138.126</span></p></td></tr><tr><td ><p class=\"\"><span >100</span></p></td><td ><p class=\"\"><span >138.506</span></p></td><td ><p class=\"\"><span >138.885</span></p></td><td ><p class=\"\"><span >139.264</span></p></td><td ><p class=\"\"><span >139.643</span></p></td><td ><p class=\"\"><span >140.022</span></p></td><td ><p class=\"\"><span >140.400</span></p></td><td ><p class=\"\"><span >140.779</span></p></td><td ><p class=\"\"><span >141.158</span></p></td><td ><p class=\"\"><span >141.536</span></p></td><td ><p class=\"\"><span >141.914</span></p></td></tr></tbody></table>"

What does the Pt100 formula say?

对于金属温度传感器,可以使用多项式来计算不同传感器温度所对应的传感器电阻。

二阶多项式的基本公式为:

R(T) = R0 x (1 + A x ϑ + B x ϑ²)

R0:0 °C 时的基础电阻
ϑ:以 °C 为单位的温度
A, B:传感器的特定系数

对于 Pt100,基础电阻为 100 Ω,其系数分别为 3.9083 × 10⁻³ °C⁻¹ (A) 和 -5.775 × 10⁻⁷ °C⁻² (B)。将这些数值代入多项式,即可得出 Pt100 的计算公式:

R(T) = 100 Ω x (1 + 3.9083 × 10⁻³ °C⁻¹ x ϑ - 5.775 × 10⁻⁷ °C⁻² x ϑ²)

该公式适用于正温度范围。

Are there other nominal resistors?

铂传感器也存在 0°C 时基础电阻为 1000 欧姆等其他规格。其他标称电阻值虽然也能生产,但较为罕见。

For which temperatures is a Pt100 suitable?

薄膜技术允许在 -70°C 至 +600°C 的范围内进行测量。

What about the Pt100 accuracy?

公差同样在标准中进行了规定。对于薄膜电阻器,其公差等级(即 Pt100 准确度等级)分为从 F 0.1(高精度)到 F 0.6(低精度)等不同级别。根据标准,公差或极限偏差是通过将测量温度代入相应的公式来确定的。

"<table class=\"table jumo-table\" data-lexical-row-striping=\"false\"><tbody><tr dir=\"ltr\"><th dir=\"ltr\" colspan=\"2\"><p class=\"\" dir=\"ltr\"><span >Pt100 accuracy classes</span></p></th></tr><tr><td>Tolerance classes</td><td>&lt;b&gt;Boundary deviation [K]&lt;/b&gt;</td></tr><tr><td>F 0,1</td><td>±(0,1 + 0,0017 x ItI)</td></tr><tr><td>F 0,15</td><td>±(0,15 + 0,002 x ItI)</td></tr><tr><td>F 0,3</td><td>±(0,3 + 0,005 x ItI)</td></tr><tr><td>F 0,6</td><td>±(0,6 + 0,01 x ItI)</td></tr></tbody></table>"

以下是两个计算示例:

F 0.1 级传感器在测量温度为 100°C 时的公差确定:
±(0.1 + 0.0017 × |100|) = ± 0.27 K(相当于 ±0.27°C)

F 0.3 级传感器在测量温度为 400°C 时的公差确定:
±(0.3 + 0.005 × |400|) = ± 2.3 K(相当于 ±2.3°C)

What are the advantages of a Pt100?

Pt100 传感器具有极佳的长期稳定性,这主要归功于其感温材料铂(Platinum)。传感器的特性曲线已实现标准化,只要评估单元中内置了该特性曲线,就能对温度信号进行准确评估。得益于这种标准化,传感器或组装式温度计的备件采购变得十分便捷。