Comparison: Rosemount 1066 vs Hamilton H100

If you’re stuck in a situation where you need to replace a pH electrode over and over, then you’ll definitely want to extend its life. My colleague Gustavo Queiroz has written an article here on Visaya on three ways to do that. And if you’re looking for help from this comparison, you should read that article.

Why? Because many field transmitters can monitor your sensor performance and act to extend the life of your sensor. Or I should say, many advanced field transmitters with fancy diagnostics can do that. The transmitters we review here can’t, so you’ll need those tips to make the most of your electrodes.

The comparison

Both analytical transmitters today are entry-level devices in their vendor portfolios. However, you can still do a lot of things using a simple transmitter – like save money. And other stuff, of course. But enough of that!

Let’s say hello to the Rosemount 1066 from Emerson Automation Solutions. Y’all should know them pretty well by now, but if you want to know more, then check out the site. On the other side, we have new bloood! The gang from Hamilton is bringing the H100 to play with us. Let’s see what’s gonna happen.

Grab a burger, have a read, and draw your conclusions!

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 Rosemount 1066 sticks with a traditional design, just like all the other entry-level devices. Shocker, I know, but come on. You can’t expect much at this level, and at least you can leave one factor out of your decision making here.

Back to the 1066. It has a local keypad to set up the transmitter and check diagnostics. The keypad feels like an 80s flashback, but menu navigation is clear and intuitive, saving you time. It also has a long display, 58 x 78 millimeters, to review your relevant process variables, menu tree, and diagnostics. In general, it provides a good user experience and lets you shelve the technical manual.

Unboxing Rosemount 1066 vs H100
Courtesy of Emerson Automation Solutions and Hamilton

The H100 during the unboxing looks like everybody else too. Fair enough. The display has seven segments and icons but no backlight on the display. Better have your flashlight handy if you work the night shift.

The local keypad has a simple design, which you should expect, of course. So why was I expecting more? Hard to say. However, to give Hamilton some credit, the user experience is decent.


Both devices are multi-parameter, which means you can measure different process variables with only one transmitter. Sort of. Each device has only one input, so you need to choose what you want to measure. Still, you can use the same platform to measure different variables, making things a little easier.

On the Emerson side – are you ready for this? I need a deep breath myself. Okay, the Rosemount 1066 can measure pH/oxidation-reduction potential (ORP), resistivity, conductivity, percent of concentration, chlorine, monochloramine, dissolved oxygen, dissolved ozone, and temperature. Whew! No shortage of options here!

Hamilton has a few options too, but this company takes a slightly different approach. You have the H100 as the basic device. But for conductivity, chlorine, or whatever other measurements, you have to choose the H100 pH, H100 DO, H100 COND, or H100 CONDI. Seems overly complex to me. Anyway, you can measure pH/ORP, conductivity, and dissolved oxygen.

Housing and approvals

The datasheet of the Rosemount 1066 says it’s 155 x 155 x 139 millimeters and weighs approximately 1.5 kilograms. Say it with me now – just like everybody else. Or pretty close, anyway.

It has a polycarbonate enclosure with a protection level of IP66, which is fine, although it could use at least one more option. If you work in food and beverage, you’ll want stainless steel and IP69K, right? On the other hand, if you work in a hazardous area, you might do okay with this one. It has approvals such as CSA, ATEX, and IECEx.

Housing Rosemount 1066 vs H100
Courtesy of Emerson Automation Solutions and Hamilton

Had to do a little digging to get the deets on the H100 but found that it’s a tad smaller and lighter than the 1066 at 144 x 144 x 105 millimeters and nearly 1 kilogram. It has a enclosure of polybutylene terephthalate (PBT) and a protection level of IP65. However, I didn’t find information on approvals; I have to assume you can’t use it in hazardous areas. If someone from Hamilton wants to point me to the proper information, drop me a comment!

Power and protocols

Okay, here we have a big difference in both points. The Rosemount 1066 is a loop-powered device, giving you communication in the same pair of cables you use to power the transmitter. The digital protocols are bog-standard for Emerson – analog, HART, and FOUNDATION Fieldbus. Not much, but better than the next.

Sadly, the H100 has zero digital protocols, just analog. Yes, it’s entry-level, but so is the 1066. Hamilton could at least provide HART, right? And it’s also 4-wire, meaning it has a pair of cables for power and another pair for communication. Simple can be good! You should check the price points on these and see how much value you get.

Fancy features

Nope, nothing here! You can find fancy devices over yonder. Next!

Information and documentation

I lost count of how many times I’ve reviewed the Emerson website. Solid user experience, even on your phone or tablet. If I were to nitpick, I’d say the Rosemount 1066 page could use some TLC, or at least better organization. It feels like somebody just slapped on the info from the old website.

Website Rosemount 1066 vs H100
Courtesy of Emerson Automation Solutions and Hamilton

The Hamilton website is not responsive and not navigable with phone or tablet. Sad, I know. But it is clear, with fairly easy navigation. The documentation on the device page, though? Yikes. Somebody get on that, please.


The Rosemount 1066 has digital protocols and loop power, if you like those things. They’re not necessary but can help. The H100 lacks these options but could still work for you if you want to keep things simple and relatively cheap. Scale them out and check the prices!

Table of comparison


Table of Comparison Rosemount 1066 vs Hamilton H100
Courtesy of Emerson Automation Solutions and Hamilton


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