Honeywell STD800 vs Siemens SITRANS P500
Here we are again, comparing two nice products, but today we have a special moment. Yes, indeed. Today, you bear witness to the first pressure device comparison on Visaya! You could even call it a landmark moment, if you wanted to play along with me.
Anyway, we have two big vendors here for this landmark post. Both of them offer good solutions for your instrumentation and automation systems, but I daresay they generally focus on system control more than instrumentation.
On the right, the competitor in turquoise brings a lot of experience to the ring! Say hello to the SITRANS P500 from Siemens! On the left, wearing scarlet and totally zoomed in on the win, we have the STD800 from Honeywell!
Both competitors have decent features for us to explore. So let’s check the real potential of each transmitter and how they can actually help you.
Take a seat, grab a Berliner, have a read!
Full disclosure: This comparison covers only the features of the device, not the performance. If any community members have installed and used these devices, please comment below with your experiences so we all can learn more. Thanks!
The two boxes before me gave me good surprises when I opened them. In them, I found pressure transmitters! I thought I might find dead bugs, so imagine my elation! Okay, enough clowning. Let’s dig in.
The Honeywell STD800 has a basic design and standard connections. It comes with a good display and the ability to set up the transmitter locally without a field communicator.
The P500 looks robust to the point of rustic, square without many curves. It also has a local display and push buttons to let you set up the transmitter in the field without special tools. Both of these devices come off pretty meh here.
The STD800 has two display options. You start out with the basic alphanumeric LCD, which gives you data in 2 lines and 16 characters, plus different ways to angle the display (0, 90, 180, or 280 degrees). Fair enough. Then Honeywell tossed in for free a square root output indicator! That’s kinda nice, I guess.
The advanced graphics LCD adds three different formats, standard process variable, bar graph, and trend graph. You also get the diagnostic on the display. And to make everything comprehensive, it gives you multiple language options. Nice, huh?
The P500 makes its display optional, with no special features. Basically, it’ll show you the process variable and relevant messages. Plus it can guide you through doing zero adjustments in the field. The manual provides very little info on it, but then it does very little, so that makes sense. Round goes to Honeywell!
The Honeywell STD800 has a piezoresistive sensor and offers static pressure and temperature measurement, for compensation and highly accurate information about your process. It has a pretty wide pressure range too, allowing you to apply the transmitter in different applications without issue.
Of course, you may need a certain type of diaphragm material for chemical compatibility. The STD800 has a nice variety, like stainless steel, Hastelloy, tantalum, and others. And for fill fluid, you have four different options to choose for your application.
The P500 sings a similar song. It also has piezoresistive sensor technology, static and temperature measurement, and lists of different material for the diaphragm and fill fluid. Tie for this one!
And here we come to the most important point. As always, remember to scale out these transmitters to check accuracy and offset before choosing.
The Honeywell STD800 has an accuracy up to 0.035 percent as standard and 0.025 percent as a special option. The stability of the sensor reaches 0.01 percent of its upper range limit (URL) per year for ten years. Good, huh?
On the Siemens side, the P500 brings good accuracy as well. It has up to 0.03 percent accuracy and stability of 0.05 percent for 5 years, with 0.08 percent for 10 years. Not at all bad, either of these, although the STD800 edges the P500 out in stability.
What protocol do you need? I hope a basic one, because you won’t find a rich list of options here. The Honeywell STD800 offers analog, HART, FOUNDATION Fieldbus and a proprietary protocol called Honeywell Digitally Enhanced (DE). If you have a different protocol, then you need to keep looking. I really miss PROFIBUS PA here.
The P500 has only the 4-20mA and HART, nothing else! I don’t understand why. However, you have a bunch of different protocols in other models, like the P410 and DSIII. You may want to investigate those.
We lack real seamless integration here. Smells like a double-KO to me, but we have to keep going! Get those fighters back up and let’s move to the next round!
Information and documentation
The Honeywell website could use some work. You can find information on it, but not easily. And if you have to use your smartphone, make sure you have something else to while away the load times. At least the documentation is readable, and you can navigate quickly through it to find the information you need.
The Siemens site needs work, too. It makes finding documents hard, and when you need to download a file, you have to search for the device again. Frankly, it sucks. On the bright side, they have a mobile version which is actually more user-friendly than the desktop version! The documentation could use some work as well. Siemens jams a lot of information on single pages with poor navigation tools. Apples and oranges for this round.
Honeywell highlights the STD800’s modular design, where you can easily exchange the electronics and modules. However, most vendors offer the same thing without making a fuss about it, which leaves this as a lukewarm feature.
The P500 also makes noise about the modular design and the advanced diagnostics, but it’s not a big deal either. No fancy features in these devices, I gotta say.
You have top devices from Honeywell and Siemens when you want accuracy and stability. They lack certain appealing points, like seamless integration, but in general, either device will suffice for many applications. Looks like the STD800 may just barely win this fight on a technicality.
What do you think?