--- title: The limitation of the minimum measurement range (size) of an infrared thermometer description: 放射温度計には測定範囲があります。測定範囲よりも測定物が小さい場合、周囲を含めて測定（視野欠け）をしてしまうため、正確な温度測定ができません。最小測定範囲は各製品によって決まっています。近づいて測定しても、最小測定範囲より小さい測定対象物は温度を測定することができません。D:S比にも注意する必要があります。 image: https://blog.aandd.co.jp/hubfs/AD-5635-Nov-08-2022-04-46-02-8769-AM.png --- - Call: 123 4561 5523 - Email: info@edumind.com - [Login](https://blog.aandd.co.jp/en/gpdme/ad-5635/home?hsLang=en) - [Register](https://blog.aandd.co.jp/en/gpdme/ad-5635/home?hsLang=en) [![A&D Company, Limited](https://blog.aandd.co.jp/hs-fs/hubfs/Logo/A%26D%20DiscoverPrecisionLogo-RGB-2.png?width=161&height=40&name=A%26D%20DiscoverPrecisionLogo-RGB-2.png "A&D Company, Limited")](http://aandd.jp) - [Home](https://www.aandd.jp/) - [Products](https://www.aandd.jp/products/products.html) - [DSP](https://www.aandd.jp/products/dsp/dsp.html) - [Test and Measurement](https://www.aandd.jp/products/test_measuring/test_measuring.html) - [Weighing](https://www.aandd.jp/products/weighing/wproduct.html) - [Inspection Systems](https://www.aandd.jp/products/inspection_systems/inspection_systems.html) - [Medical](https://www.aandd.jp/products/medical/medical.html) - [Automotive](https://aanddtech.com/) - [Company](https://www.aandd.jp/company/company.html) - [Message](https://www.aandd.jp/company/company.html) - [Company Profile](https://www.aandd.jp/company/company_profile.html) - [Company History](https://www.aandd.jp/company/company_history.html) - [World Wide](https://www.aandd.jp/company/contact_us.html) - [Investor Relations](https://www.aandd.jp/ir/ir.html) - [Support](https://www.aandd.jp/support/support.html) - [Blog](https://blog.aandd.co.jp/en) - [FAQ](https://support.aandd.co.jp/en/faq?hsLang=en) - [Contact](https://www.aandd.jp/company/contact_us.html) [![A&D Company, Ltd.](https://blog.aandd.co.jp/hs-fs/hubfs/%E5%90%8D%E7%A7%B0%E6%9C%AA%E8%A8%AD%E5%AE%9A%201-1.png?width=163&height=40&name=%E5%90%8D%E7%A7%B0%E6%9C%AA%E8%A8%AD%E5%AE%9A%201-1.png "A&D Company, Ltd.")](http://aandd.jp) close D:S Distance : Measurement range ## The limitation of the minimum measurement range (size) of an infrared thermometer - June 27 2023 - Riho Kato ![放射温度計 AD-5635](https://blog.aandd.co.jp/hubfs/AD-5635-Nov-08-2022-04-46-02-8769-AM.png)     An infrared thermometer has a measurement range. If the measured object is smaller than the measurement range, accurate temperature measurement cannot be achieved. This is because the measurement includes the surroundings of the measured object, resulting in a field of view deficiency. ![Measurement range](https://blog.aandd.co.jp/hs-fs/hubfs/Measurement%20range.png?width=866&height=352&name=Measurement%20range.png) The minimum measurement range (determined by the size of the lens) is specific to each product. Objects smaller than the minimum measurement range cannot be measured for temperature.   When measuring with an infrared thermometer, it is also important to consider the D:S ratio.    （Reference:  　[The relationship between the distance＆ measurement range(D:S)](https://blog.aandd.co.jp/en/gpdme/ad-5635/dshi?hsLang=en)) ![Distance Measurement range Example](https://blog.aandd.co.jp/hs-fs/hubfs/Distance%20Measurement%20range%20Example.png?width=727&height=318&name=Distance%20Measurement%20range%20Example.png) In the example shown above, the minimum measurement range is 2.5cm, which means that the diameter of the target object must be at least 2.5cm. Even if the distance is within 1.5m, the measurement range will still be 2.5cm.   At A&D, we offer infrared thermometers with a minimum measurement range of 10mm.     （Reference: 　[How to choose an infrared thermometer](https://blog.aandd.co.jp/en/gpdme/ad-5635/kishyusentei?hsLang=en) ）           ###### Tags: [D:S Distance : Measurement range](https://blog.aandd.co.jp/en/tag/ds-distance-measurement-range) [AD-5635](https://blog.aandd.co.jp/en/tag/ad-5635) [The minimum measurement range](https://blog.aandd.co.jp/en/tag/the-minimum-measurement-range) [![A&D DiscoverPrecisionLogo-White-RGB (1)-1](https://blog.aandd.co.jp/hs-fs/hubfs/A%26D%20DiscoverPrecisionLogo-White-RGB%20(1)-1.png?width=250&height=136&name=A%26D%20DiscoverPrecisionLogo-White-RGB%20(1)-1.png "A&D DiscoverPrecisionLogo-White-RGB (1)-1")](http://aandd.jp) 3-23-14, Higashi-Ikebukuro, Toshima-ku, Tokyo 170-0013, Japan ### Products - [DSP](https://www.aandd.jp/products/dsp/dsp.html) - [Test & Measurement](https://www.aandd.jp/products/test_measuring/test_measuring.html) - [Weighing](https://www.aandd.jp/products/weighing/wproduct.html) - [Inspection Systems](https://www.aandd.jp/products/inspection_systems/inspection_systems.html) - [Medical](https://www.aandd.jp/products/medical/medical.html) - [Automotive](https://aanddtech.com/) ### Company - [Message](https://www.aandd.jp/company/company.html) - [Company Profile](https://www.aandd.jp/company/company_profile.html) - [Company History](https://www.aandd.jp/company/company_history.html) - [World Wide](https://www.aandd.jp/company/contact_us.html) ### [Support](https://www.aandd.jp/support/support.html) Enter your email address to register to our newsletter subscription (c) 2025 A&D Company, Limited All Rights Reserved. ```json { "@context" : "https://schema.org", "@type" : "BlogPosting", "author" : { "@type" : "Person", "name" : "Riho Kato", "url" : "https://blog.aandd.co.jp/en/author/riho-kato" }, "dateModified" : "2023-06-27T01:30:40.369Z", "datePublished" : "2023-06-27T01:29:21.000Z", "headline" : "The limitation of the minimum measurement range (size) of an infrared thermometer", "image" : [ "https://blog.aandd.co.jp/hubfs/AD-5635-Nov-08-2022-04-46-02-8769-AM.png" ], "mainEntityOfPage" : { "@id" : "https://blog.aandd.co.jp/en/gpdme/ad-5635/saisyousokuteihanni", "@type" : "WebPage" }, "publisher" : { "@type" : "Organization", "logo" : { "@type" : "ImageObject", "url" : "https://blog.aandd.co.jp/hubfs/Logo/AandD%20DiscoverPrecisionLogo/A&D%20DiscoverPrecisionLogo-RGB-3.png" }, "name" : "A&D COMPANY, LIMITED" } } ```