Category Archives: Sensor

Accurate Instruments are Essential When Measuring for Thermal Management Solutions

Posted on August 14, 2026 by | Leave a comment

By collecting and analyzing more relevant measurement data, electronic cooling systems can be designed for improved performance, reliability, and cost. It’s essential these measurements be as accurate as possible. Critical data points include component temperature, air temperature, air flow rate, and often air pressure. Accuracy becomes even more important when performing accelerated testing as seen in this post.

Research-grade instruments and specialized sensors, properly calibrated and operated, can measure chip temperatures and surrounding elements, such as local airflow. Separate instruments can be used to quantify specific conditions, but more real-use data is obtained when all points are collected simultaneously. Taken over a range of time and conditions, simultaneous measurements provide more accurate, actionable information. They also reduce the cost and set-up time for multiple studies.

Fig 1 – Input Ports for a Laboratory Instrument that Simultaneously Measures Air Velocity, Temperature and Pressure. [ATS]
Fig 2 – High-quality Thermal Data Reduces Uncertainties in Cooling Solutions than Calculated Data. [ATS]

Accelerated Product Reliability Testing

Reliability testing at different temperatures and conditions is commonly performed to identify expected product life. When an electronic system is running, it continuously experiences temperature and power cycling. These fluctuations are typically normal, but should be factored into a comprehensive thermal profile study.

It’s not practical to wait years to see if a component fails. Accelerated life testing provides faster predictions. A commonly used predictive tool is the Arrhenius model shown below.

Accelerated life testing using the Arrhenius model is a method for predicting how long a product will last under normal conditions by running it at elevated temperatures for a shorter time. The temperature increase speeds up the same failure processes that would eventually occur in the field—compressing years of life into weeks of testing.

Accelerated life testing Arrhenius calculators can help estimate field lifetime, test duration, acceleration factors, activation energy, and field failure rates. These tools are useful when real-time qualification can’t be done. This is typical with electronic components and devices that need fast market introduction. One such calculator is found here: Accelerated Life Test Arrhenius Calculator. [1]

The Arrhenius Model handles pure thermal stress, while the Eyring Model includes temperature plus other active forces like humidity or voltage. [1,2]

Highly Accurate Thermal Instruments

Besides its design, a thermal instrument’s construction and calibration should be high quality, and not a source of more errors. Accurate, research-grade instruments are essential for valid engineering practices. Without them, reliability predictions for a new product are actually less reliable themselves.

Fig 3 – Candlestick Sensors are Thin Profile (0.5 mm) with a Small Base (9.5 mm dia) for Collecting Air Temperature and Velocity Data at Single or Multiple Locations. [ATS]
Fig 4 – Here, Air Temperature and Velocity Measurements are Taken Every Second by an eATVS-8 Instrument. stageVIEW Software Provides a Wide Range of Data Collection Choices. [ATS]



Here are some of the ATS instruments available for temperature and velocity measurement and providing the highest-quality thermal reliability test results.

Conclusion

Temperature has a significant effect on reaction rate and the subsequent reliability prediction. Small errors in temperature and airflow measurements can significantly impact reliability predictions. Such errors typically occur in the measurement process or from using inaccurate instruments.

If thermal data is inaccurate, outcomes can include over-designed systems, cost overruns, and products not shipping.

Laboratory-quality thermal instruments can reduce or eliminate measurement and calculation mistakes, leading to higher quality, faster to market and ultimately lower cost products. Just as important, collected data needs to be correctly interpreted. Expert thermal engineers can do just that with data provided or that they obtain themselves.

More information on these topics can be seen at these ATS videos:

How to Properly Measure Air Velocity in Electronic Systems [Link] [3]

How to Perform and Understand Temperature Measurement within Electronic Systems [Link] [4]

stageVIEW Software Demo [Link] [5]

References

  1. Firgelli Automations, https://www.firgelliauto.com/blogs/calculators/accelerated-life-test-arrhenius-calculator
  2. NIST, https://www.itl.nist.gov/div898/handbook/apr/section1/apr152.htm
  3. Advanced Thermal Solutions, Inc., https://vimeo.com/reviews/a4e9a72d-d228-489f-8edb-a98e440a8ef1/videos/113427506
  4. Advanced Thermal Solutions, Inc., https://vimeo.com/reviews/63784f1b-a32d-4f90-86b1-5bf362715619/videos/113432468
  5. Advanced Thermal Solutions, Inc., https://www.youtube.com/watch?v=Lx5NlAI5TuM

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Posted in Analysis, Consulting, Engineering, Instrument, Sensor, Thermal Design, thermal engineering, thermal management

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ATS Wind Tunnels Designed for SSD and PCIe Thermal Characterization

Posted on February 1, 2019 by | 45 comments

As was outlined in an earlier article on this blog, it is critical for manufacturers to characterize solid-state drives (SSD) to establish performance parameters in real-world conditions. The previous article explained that SSD experience higher failure rates and reduced lifespan when temperatures increase beyond the standard operating range of 30-40°C.

Wind Tunnels
ATS designed wind tunnels for companies looking to characterize solid-state drives in the PCIe form factor, as show above. (Wikimedia Commons)

Testing processes for SSD are similar to those used for characterizing typical semiconductors. A wind tunnel provides a consistent, controlled, and repeatable environment for data collection and sensors, thermocouples, and an analog-to-digital capture system allows engineers to measure performance when the SSD is impacted by external factors.

ATS designs and fabricates research-quality wind tunnels that can be used for characterizing SSD. The wind tunnels give engineers control over air temperature and velocity. Closed-loop wind tunnels can create environments with temperatures as high as 80°C to provide stressed conditions well above standard operating temperatures. The manufacturer can use this data to set reference points for different environments, such as in 1-U telecommunications chassis or large server boxes.

Recently, ATS has worked with two of the industry’s largest producers of SSD to design wind tunnels that could be used for characterizing drives in PCIe applications. PCIe (peripheral component interconnect express) cards are high-speed serial computer extension cards that connect peripheral devices to the motherboard. In addition to SSD, these cards can be used for graphics processors, Wi-Fi, or other hard drives.

ATS wind tunnels can be used to test airflow and thermal performance for components and boards, as shown in this smoke flow visualization test over a maxiFLOW™ heat sink. (Advanced Thermal Solutions, Inc.)

One of the wind tunnels was a standard, open loop CWT-107™. It can produce uniform and homogeneous flow, up to 5.5 m/s (1100 ft/min) within the wind tunnel’s test section due to its polynomial shape and internal flow management system, which features honeycombs and screens to break up turbulence. The wind tunnel can be operated either vertically or horizontally and the customer chose to use it lying down.

In fact, the customer was very creative in its use of the wind tunnel. A customized cart was built for the wind tunnel to be bolted to and then the cart was wheeled into a large environmental chamber where temperatures could be raised to test levels. The SSD being characterized was a PCIe card with memory installed. There was no fan for the memory and the memory had no shielding or housing.

The customer placed its PCIe-based SSD flat in the test chamber. Power was pulled through the test ports included in the test chamber of the CLWT-107™ (as shown below).

While the wind tunnel was bought for testing SSD, it could be used by the customer to test any electronic component or board.

The second customer purchased a CLWT-115™ closed-loop wind tunnel. In this case, the application required the SSD to be powered through the PCIe back plane, so ATS custom-designed slots in the test section to fit the PCIe form factor. The slots allowed the SSD to remain inside the test section and be connected to a motherboard residing outside the wind tunnel (see below).

Again, the wind tunnel could be used to test any PCIe cards, not just SSD, if the customer desired, as there were also fillers created for the slots to allow the wind tunnel to be used when testing other devices.

The second customer did all of its air velocity and temperature testing in the CLWT-115™, rather than using an environmental chamber like the first customer, because the wind tunnel has a self-contained heating unit that heats air while it circulates during testing.

Wind tunnel controllers and ATVS systems were also purchased by both customers to ensure accurate data collection. The first customer bought an ATVS-NxT™, which is a fully portable scanner that operates with an embedded PC and touch screen control, while the second customer bought the ATVS-2020™, which allows single- or multi-point measurement of both temperature and velocity, and a CLWTC-1000™, which automatically controlled the airflow and temperature through the test chamber.

Both come with Candlestick sensors to control the air velocity in the wind tunnel and thermocouples to control the temperature.

One of the customers also requested a custom, rugged sensor to avoid damage through multiple uses. ATS was able to adapt one of its handheld surface probes, a stainless-steel probe with a pointed tip for exact positioning of the sensor on the desired spot, by reducing the length and designing a custom port that would hold the sensor in place.

SSD are gaining traction in the market, with major hard drive manufacturers and the companies that utilize them both making the switch to solid-state technology. This means that thermal characterization of SSD and thermal management systems deployed to dissipate the heat of these drives are going to be of increasing importance in the coming years.

Using research-quality wind tunnels gives manufacturers a leg up in determining how their drives will perform in different real-world environments and makes the process of SSD characterization easier for users. By working with ATS, companies can tailor their wind tunnels to their specific applications and can be assured of the accuracy of the data that they collect.

Learn more about ATS wind tunnels, sensors, and the entire line of next-generation thermal test instruments at https://www.qats.com/Products/
Instruments. If you have questions about any products or ATS thermal testing services, email [email protected].

For more information about Advanced Thermal Solutions, Inc. (ATS) thermal management consulting and design services, visit https://www.qats.com/consulting or contact ATS at 781.769.2800 or [email protected].

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Posted in Case Studies, Sensor, Wind Tunnel

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An Instrument for Measuring Air Velocity, Pressure and Temperature in Electronics Enclosures

Posted on May 29, 2012 by | Leave a comment

For engineer-level thermal management studies, the iQ-200 instrument from Advanced Thermal Solutions, Inc, ATS, can simultaneously measure air velocity, air pressure and the temperature of components and surrounding air at multiple locations inside electronic systems. This enables users to obtain full and accurate profiles of components, heat sinks, PCBs and other electronics hardware to enable more effective thermal management.

Developed by Advanced Thermal Solutions, Inc., ATS, the iQ-200 system simultaneously captures data from up to 12 J-type thermocouples, 16 air/velocity sensors, and four pressure sensors.

The thermocouples provide surface area temperature measurements on heat spreaders, component packages, housing hardware, and elsewhere to track heat flow or detect hot spots. Temperature data is tracked from -40 to 750°C. The sensors (available separately) measure both air temperature and velocity at multiple points allowing a detailed analysis of airflow.

Candlestick Sensor from ATS

Thin, low profile ATS candlestick sensors can be easily positioned throughout a system under test and measure airflow from -10 to +6°C. Air velocity is measured from natural convection up to 6 m/s (1200 ft/min). The iQ-200 can be factory modified to measure airflow to 50 m/s (10,000 ft/min) and air temperature up to 85°C. Four differential transducers capture pressure drop data along circuit cards, assemblies and orifice plates. Standard pressure measurement capabilities range from 0- 1,034 Pa (0 – 0.15 psi).

The ATS iQ-200 system comes preloaded with user-friendly iSTAGE application software which effectively manages incoming data from the various sensor devices, and allows rich graphic presentation on monitors and captured on videos or documents. The iQ-200 connects via USB to any conventional PC for convenient data management, storage and sharing.

More information on the iQ-200 system from ATS can be found on Qats.com (http://www.qats.com/products/Temperature-and-Velocity-Measurement/Instruments/iQ-200/2632.aspx), or by calling 781-769-2800.

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Posted in Instrument, Sensor, Thermal Analysis, thermal engineering, thermal management, Thermal Research, Thermal Science, Uncategorized

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New Electronics Cooling Webinars are Open for Second Quarter of 2012

Posted on April 3, 2012 by | Leave a comment

Each month during the second quarter of 2012, ATS will present a technical webinar covering different topics within the dynamic world of electronics cooling. Each of these one-hour, online tutorials will include detailed visuals, definitions, instructions, case studies and references. One or more ATS PhD-level thermal engineers will be presenting live. Viewers will be able to key in questions during and after the presentation.

Each Q2 webinar is planned for a Thursday afternoon (ET) late in the month. These are the second quarter topics for the ATS webinars:

April 26, 2012 at 2:00 p.m. ET

How to Perform and Understand Air Velocity Measurement within Electronics Systems

Participants will learn about the importance of measuring air velocity in a system, the instruments necessary for obtaining useful measurements and where these velocities should be recorded.

May 24, 2012 at 2:00 p.m. ET

CFD as a Tool to Perform Heat Sink and System Modeling

Computational Fluid Dynamics (CFD) tools have become indispensable simulation tools, enabling design engineers to confront electronics cooling challenges on demand. Some tips and tricks are invaluable in performing these analyses. Among them: the simplest methods of preparing a CFD model; the best techniques for meshing; and how to model a systems components, such as fans and perforated plates. Attendees will learn about common and not-so-common issues in CFD, and how to overcome them.

June 28, 2012 at 2:00 p.m. ET

Heat Sink Selection Made Easy

As heat dissipation needs for electronic devices rapidly grow, choosing the right heat sink the first time is essential. With so many application requirements and heat sink options, this can be a daunting task. In this webinar, attendees will learn about the importance of system airflow and its impact on heat sink design; attachment methods; and how to solve thermal design challenges.

Seats at each of these webinars are free, but limited. Registration is available online at http://www.qats.com, or by calling 1-781-949-2522.

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Posted in CFD, heat sink, Sensor, thermal management, Training, Webinar

Sensors for Temperature Measurement and Their Application (part 3 of 3)

Posted on February 1, 2012 by | Leave a comment

Today we conclude our three part series, “Sensors for Temperature Measurement and Their Application”. We’ll be talking about the last three sensor types: Infrared or Radiation, Fluorescent Detector and Liquid Crystal. To catch up on the series, you can click to Part 1 of our series or click over to Part 2 of our series.

4. Infrared Thermography

Infrared thermography works on the basis of the IR waves emitted from a heated surface. The infrared system captures the waves, and based on internal calibration converts them into temperature. The following are required for IR-based measurements:

  • Infrared imaging system — The market offers a broad range, but a worthy system starts at around $30-70k. For IR microscopy (down to 5mm only-lower limit of IR wave-length), the system starts at $180k.
  • Signal processing equipment.
  • Knowledge of emissivity if the test specimen must be coated with a known emissivity material.
  • Calibration.

Figures 5a and 5b show a typical IR image of heat-emitting surfaces:

IR Image of PCB Board In Forced Convection Air Flow5a shows and IR image of a PCB in forced convection air flow[3]

PCB Board IR Image in natural convection air flow5b shows and IR image of a PCB in forced natural convection air flow[3]

 

The following points are noteworthy when using an IR camera for temperature measurement:

  • Application accuracy is a function of emissivity.
  • The measurement situation must duplicate the actual environment, as far as air velocity, temperature and air flow distribution are concerned.
  • The IR camera is sensitive to reflected radiation.
  • Carbon dioxide and water vapor absorb significant energy and may cause significant error.
  • In an electronics application, surfaces typically have different emissivities thus, one must make the emissivity uniform before measurement of known emissivity (black paint or powder).
  • In most IR equipment, the temperature readout is the average over an area. Therefore, temperature peaks may be ignored as the result of integration. To remedy the situation, better IR optics must be used to reduce the area where integration occurs.

5. Optical Probes

Optical sensors are light-emitting devices that illuminate the test body with source radiation, and can detect reflected radiation, or simulated radiation such as fluorescence. Although not broadly used, optical probes are used at the die or component level. Figure 6 shows one such a probe.

Optical probe for temperature measurementFigure 6. Optical Probe For Surface Temperature Measurement The Probe Either Touches The Surface Or Captures The Reflected light From A Fluorescent Treated Surface.

6. Liquid Crystal Thermography

LC thermography works on the basis of visible light reflected from a surface treated with the LC material. The system captures the reflected wavelengths, and based on internal calibration, converts them into temperatures. Liquid crystals (LCs) are cholesteric materials. When applied to a heated surface they realign and reflect light at a different wavelength. The reflected light shows the standard colors seen in a rainbow. Figure 7 shows the application of LCs on an IC.

Liquid crystal color display on a semiconductorFigure 7. Color display of liquid crystal applied on an IC. Blue reveals the circuit’s hottest point, and black shows that the temperature is outside the range of the crystal material [3].

The following are salient features of LC material:

  • Liquid crystals are organic compounds that can be poured like a liquid, yet reflect light like a crystal.
  • Changes in LC optical properties can be produced by externally applied fields (e.g., electrical, magnetic, and thermal).
  • Cholesteric liquid crystals progressively exhibit all colors of the visible spectrum when heated over their event temperature range.
  • Width and placement of the event temperature range can be controlled by selecting and mixing the appropriate liquid crystals.
  • Liquid crystals are commercially available with event temperatures ranging from below 0oC to 160oC, with spans ranging from 1 to 50oC.

An LC thermography system such as the one shown in Figure 8 can provide a very effective temperature-mapping system.

thermVIEW LCD Instrument from Q ATS

Figure 8: The thermVIEW System for Macro and Microscopic (down to 1um) Surface Temperature Measurement[4]

Figure 9 shows a typical result of LC thermography at die level:

Temperature distribution across a memory chip
Figure 9. Temperature distribution across a memory chip (5 x 5 mm) at Tambient = 25oC, as shown using Liquid Crystal Thermography [3].

Like any other system for temperature measurement, LC thermography offers distinct advantages and disadvantages. One salient advantage of LC thermography is that its not dependent on surface emissivity. A second is that at micron and submicron levels, though not a trivial task, LC thermography allows easier and less costly temperature measurements while enabling 1µm or smaller spatial resolution. One disadvantage of LC thermography is that it is not a pick-up-and-measure system like IR. One must apply the calibrated liquid crystal material to a surface in order to perform the measurement. But, this is similar to the IR system, in that you need to make the surface emissivity uniform if the measured surface has multi-emissivity (e.g., a die or PCB).

In this article, we reviewed six different probes/techniques for temperature measurement. It would be a missed opportunity not to include a word on calibration. Irrespective of the types of measurement and sensors one uses, calibration is of utmost importance. Pay special attention to the calibration process and ensure that the sensors are properly calibrated. Further, one needs to ensure that the chosen sensor is suitable for the type of measurement. As Prof. Frank White states in his Viscous Flow book, Bad data is worse than no data at all [5].

To catch up on the series or read from the start, you can click to Part 1 of our series or click over to Part 2 of our series.

References

  1. Klinger, D., Nakada, Y., Menendez, M., AT&T Reliability Manual, Van Nostrand Reinhold, 1990.
  2. Azar, K., Thermal Measurement in Electronics Cooling, CRC Press, 1997.
  3. Advanced Thermal Solutions, Inc., Tutorial Series, Principles of Temperature Measurement.
  4. thermVIEW System, product of Advanced Thermal Solutions, Inc.
  5. White, F., Viscous Fluid Flow, McGraw-Hill, 3rd Ed., 2005.

If you are in need of sensors for thermal measurement, click now to ATS’ sensor family. To learn more about ATS ‘ thermVIEW liquid crystal thermal analysis system, click to thermVIEW System. You can also email or call us with your questions on temperature measurement and one of our engineers will be happy to help you. Email us at [email protected] or call us at 781-769-2800.

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