Product Review: PR Electronics 7501
We’re talking temperature again here on Visaya! Go look at our new #WishIknew series, where I answer questions related to temperature measurement. We also have videos on this subject in the Visaya Weekly, with more on the way!
Some temp devices have only one channel, but many offer dual inputs so you can measure two points. Better yet, you can use the second channel as a redundant input, so you won’t lose data if a sensor fails.
A few transmitters with different protocol options have more than two inputs, but only three companies come to mind with those – Emerson, Yokogawa, and SMAR. So how come no one else has them? Maybe these devices don’t fit in the “company strategy.” But based on my experience visiting customers and seeing their pain, especially in industries like mining and metals, some of y’all are missing a good opportunity.
Okay, sorry to make you wait! And yes, we have yet another new team visiting Visaya! PR Electronics presents the 7501 field-mounted HART temperature transmitter. Let’s see its potential and how you can fit in your 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.
Whatcha got there?
I’ve never heard of this company before, but the PR Electronics 7501 impressed me from the start! Although the design seems fairly standard, it has an amazing display and touchscreen to catch your attention.
The high-definition display sports 96 x 64 pixels and can adopt different orientations. With it, you can see the process variables, diagnostics, and device menu. Its also bar graph helps you do a quick read of the temperature range and its percentage in the total measuring range. If you have an issue with the device or sensor, the transmitter switches its white backlight to a flashing red light that you can see from a good distance.
You can also set up locally using three optical buttons: Up, Down, and Enter. The user experience on the local configuration seems quite good, so you won’t have issues navigating the menu. And you can use the touchscreen while wearing gloves! More devices need this feature, if you ask me.
What can it do?
The PR Electronics 7501 measures temperature, right? But like many others, it also reads RTDs, thermocouples, resistance, and millivoltage input. As I mentioned in another article, you can use these inputs to connect a sensor with the same output. Then you can use the transmitter in different applications.
On the other hand, this device lacks protocol range, with just HART and analog. Sure, those two cover a lot of ground, but if you want FOUNDATION Fieldbus or PROFIBUS, then skip this one. While you can use a converter, you’re better off using a device with native protocol.
PR Electronic claims an accuracy of 0.05 percent, which gives you a decent place to start. You need your sensor info, especially its typical measuring deviation, to get real numbers on accuracy in your process.
Why should I care?
The PR Electronics 7501 has all the basics but some nifty extras as well! For starters, it has multiple approvals for hazardous areas and harsh environments. Check out the data sheet to see if it has the approval necessary for your process.
I consider the display a big plus here, particularly the backlight that switches from white to red to alert you to problems immediately. This sort of alarm in the field will help you catch issues while on site. And if you use the HART connection, then you can have the same level of data to find out remotely what’s going on.
Last but not least, the gang from PR Electronics have two patents in this device. The first covers the optical buttons with their 10-millimeter explosion-proof windows, and the second the extremely power-efficient digital communication. Patents mean progress!
The 7501 field-mounted HART temperature transmitter is a simple device with good features for your application. If you can use either HART or analog, then put this one on your candidate list!