It is frustrating that you ignore any point that shows you to be wrong and instead try to change the argument to an irrelevant tangent.
Per the distributor of the Ranco ETC, Honey Run Apiaries, the error can be larger depending on variations in the electrical source. If you disagree, please argue with the distributor.
Once again PJF you have quoted a source and taken it out of context to benefit your argument.
Lets take this IN CONTEXT:
1) Who said I disagreed with the concept that power quality could affect the unit? Power quality affects ALL electronics PJF. Your 120V wall clock is affected, your digital clocks are affected. The scan rate on your TV is affected. Just about any device that uses an analog probe will be affected by the input source. Your an EE PJF, you know (should know?) that the RANCO and every other analog probe is a simple voltage/current comparator and thus affected by the source supply.
Of course we can build around the problem and design a unit with MORE precision and de-couple it from source problems. It is pointless as already shown here and in other threads.
2) The BIGGER problem is that you have taken a fact and then twisted it around your own deceptive reasoning. You said [SIC]
"The problem will be more prevalent in a home environment due to power problems that are not present in commercial environments where the code is much stricter and the unit will be on a dedicated HVAC circuit." That is complete and utter nonsense. You know it, I know it, and any person that knows anything about electricity knows it. Did you throw it out there thinking we were all stupid?
Lets be clear so that the othe readers are not deceived by your comments:
Folks, Commercial/Industrial power is almost always MUCH worse than what you have flowing out of your homes panel. The spikes, harmonics, phase anomalies, ground loops, and unfiltered noise are a constant battle in commercial facilities. That is EXACTLY why RANCOS and similar industrial/commercial equipment are built so bulletproof.
So no, I have no argument with "Honey Run Apiares". My argument is with your distortion of facts and subsequent application of your derived truth.
Then it should be easy to post links to support your statements.
Who needs links to understand basic logic? We go through this exercise over and over.
Lets give it a try again: (We did this in 2 other threads).
1A) A RANCO is a dedicated temperature controller. It does one thing and does it well. It has a supply input, a load output and a probe input. That is (3) interfaces that could contribute to, or cause a failure.
1B) An "aquarium controller" has at least 1 supply input, several load outputs and several probe inputs. There are MANY interfaces that could contribute to, or cause a failure. The unit is simply MORE exposed.
This is basic design logic and as an EE you know (should know) it. The more nodes that are tied to a system, the greater chance the system has to fail.
The argument is over already, as the point has been made. But lets go on.
2A) The RANCO is hard coded with the only user input being set points. There is little room for user error. The driving variable is the single probe input. Bugs are easy to find and remove because the code is fixed and simple.
2B) The aquarium controller is scriptable with user input. There are MANY intertwined aspects of the units operation and the source code is much more complex. There are MANY driving variables that interact with the code. These include multiple inputs and user crafted scripts. This is a complex system that is MUCH more prone to firmware bugs AND human errors in programming logic. Debugging is much harder as all interactions can not be predicted. Human programming error is also a large problem (remember those complex interaction?).
The is really over, as the point has been succinctly made. But lets go on.
3A) The RANCO has a rather small component count and is made to withstand rugged commercial/industrial use. The circuit design is mature and proven. Low component count and robust circuit design mean low failure rates.
3B) The aquarium controller has a MUCH higher component count, much of it delicate. The circuits are NOT designed around rugged commercial/industrial use and do not have a long track record. On the contrary some units are very prone to outside interference from ballasts and lighting.
You list yourself as an EE, this stuff SHOULD be common sense to you PJF. I am baffled that somebody with your credentials would continue to make the arguments that you make.
Whether you agree with Honey Run Apiaries or not, my recommendation is to "shop around." There are plenty of choices for aquarium temperature controls. The Eheim Jager heaters are cheap and have something the Ranco does not have. They can be calibrated.
We have already covered each of those statements. Calibration is certainly not important, nor is the fact that your mains power can affect the operation of electronics.
Time to pack this one in PJF.
