I personally use the Myron L Ultra Meter 6p. It measures pH, Conductivity, Temperature, and is water resistant up to 3 feet. I actually bought mine off E-bay and sent it to Myron L for a full calibration to be on the safe side.
I agree the Myron meter is by far the most durable and is plenty accurate enough for pressroom use, but I suggest the DS model that only measures conductivity and thew use of 'ColorpHast' brand plastic pH strips for measuring pH outside of the lab. As long as the strips are kept dry and out of the light when not in use they are as accurate as a good meter and they never require calibration. The difference in cost between the Myron L DS meter and the Myron models that measure both pH and conductivity will buy a lot of strips.
I've been down this journey just recently. We use Myron-L Conductivity meters which are very good.
You have to be very careful with pH though. Measuring pH in general is VERY Finicky. You need to constantly calibrate these probes, keep them wet, it's like running a science experiment.
So, I keep a Extech meter in my office which I keep calibrated and wet. Out on the presses, I leave rolls of pH paper specially designed to measure between 3.0-5.0 pH, which fits right into our fountain solution range.
I find these to be the least finicky and simplest, low maintenance option, even though I sacrifice extreme accuracy.