Comparison: iTEMP TMT162 vs YTA320

Today we have two big companies with devices to compare here at Visaya! On the right, Endress+Hauser brings the iTEMP TMT162, a top-end transmitter with advanced features. On the left, Yokogawa presents the YTA320, one of the many options in its portfolio, promising good features as well.

Are you ready? Let’s dive in and see how both devices can fit in a new application!

Disclaimer: This product review examines only features, not performance. If you’ve used this device, feel free to share your experience in the comments.


The TMT162 has a standard design but an eye-catching display and several types of housing material and approvals. Its has dual panels, so you can connect sensors and loop power in the back and access the electronics and display in the front. The housing material makes a difference in the weight of this compact device; the aluminum and hygienic stainless steel weigh around 1.2 to 1.4 kilograms and the stainless steel for harsh environments around 4.2.

I mentioned this in the review, but I love the display on this thing. The elegant screen provides process values, bar graphs, and status information. I’ve never seen its like on any other temperature device. If you have, then let me know so I can ogle that one too! On the downside, it doesn’t have push buttons or a touchscreen for local setup. Sure, you can do it remotely or through a handheld, but a local setup seems almost standard on E+H devices, so I miss it.

Unboxing iTEMP TMT162 vs YTA320
Courtesy of Endress+Hauser and Yokogawa

On the green side, the YTA320 looks discreet but feels robust in your hands. It too has a double-panel housing with the same layout as the TMT162. Although it has housing materials like aluminum and stainless steel, I couldn’t find a hygienic option. Poor documentation or limited application? Either way, it counts as a minus. Beyond that, it has a similar weight and size to its competitor, so we’ll call that a draw.

The display doesn’t impress as much, but it provides the same level of information. Sadly, the YTA320 doesn’t have local setup either, but you can find that in the YTA610 or 710, if you want to expand your candidate pool.

Measuring input

Here the two show very little difference. You can select single or dual channels for the TMT162, and it reads a wide range of thermocouples and resistance temperature detectors (RTDs). It can also handle sensors with outputs in resistance from 10 to 2000 ohms or voltage from -20 to 100 millivolts. In the manual, you can see the entire list of sensors.

The YTA320 also has two inputs for the same variety. It can read resistance from 0 to 2000 ohms and voltage from -10 to 100 millivolts.

Field protocol and output

The blue side has more options for integration, such as HART, FOUNDATION Fieldbus (FF), and PROFIBUS PA. On the downside, it has no wireless version, despite wireless becoming close to standard now. You could use a wireless adapter on it, but it’ll suck so much battery juice you might as well choose a competitor that has wireless integrated.

The YTA320 only integrates with HART, BRAIN, and FF. I’m not impressed that someone included a proprietary protocol instead of PROFIBUS PA, but if you drink the Yokogawa koolaid, then maybe it makes sense to you. No wireless here either, but the company has a whole line with built-in wireless antennas, so guess that’s fine.

Performance and approvals

Once again, performance depends on sensors. Each vendor provides the digital accuracy of the sensors in the manual, but let’s take a look at some examples.

On the Endress side, a Pt100 has an accuracy of +- 0.1 degrees Celsius and a Pt1000 +-0.2 degrees Celsius. A sensor with resistance output in a measuring range from 10 to 400 ohms has an accuracy of +-0.04 ohms. You can use the iTEMP TMT162 in harsh or hygienic applications, as it comes with a bunch of approvals and protections for those.

Housing iTEMP TMT162
Courtesy of Endress+Hauser 

Same goes for the Yokogawa device and its sensor accuracy list. A type-E thermocouple with a measuring range from -200 to -50 degrees Celsius has an accuracy of +-3.0, and a Pt100 measuring from -200 to 850 has an accuracy of +-0.14. Furthermore, it has several approvals and protections in the manual, if you want to check those out. Still nothing on a hygienic version, but if I’m wrong, then drop me a comment and let me know.

Fancy features

For top-tier devices, they don’t have super-fancy features, but they do bring interesting possibilities with two inputs. The TMT162 has a backup function. If one sensor stops, then the device switches to the other and flags the issue without interruption. It also has sensor drift detection, which warns you when it detects a difference between the readings of the sensors based on a pre-set value.

The YTA320 can provide differential or average measurements using the two sensors. It also has the backup function and warning like the TMT162.

Information and documentation

Endress+Hauser website still sucks. Can’t access it worth a squat on phone or tablet, hard to find devices and documentation, blah. The documentation, on the other hand, is quite good. So once you find it, you can easily get the answer to your question.

Websites iTEMP TMT162 vs YTA320
Courtesy of Endress+Hauser and Yokogawa

Yokogawa has a much better site. It’s responsive so you can easily find information using your phone or tablet and better organized in the documentation department. With documentation on par with E+H’s, Yokogawa wins this round.

Table of Comparison

Table of Comparison iTEMP TMT162 vs YTA320
Courtesy of Endress+Hauser and Yokogawa


Both devices have very similar functions. If you want a PROFIBUS PA transmitter or have a hygienic application, then go with Endress+Hauser. If you’re okay with HART or FF and can’t eat the product from your process, then you need to do some research to find your best option.

Buy the iTEMP TMT162 in our online shop


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