Icstation Digital Thermometer, Car Auto Temperature Gauge Sensor, DC 4-28V Fahrenheit Dual Display, Monitor with 2 NTC Waterproof Probes for Aquarium Vehicle Fish Tank

I am pleased with this product and I think I could make good use of it. I have compared the measurements it takes against a precision temperature monitor that I have and the results are within +/- 0.5 degrees Fahrenheit (possibly better). (There is a photo showing how I connected the probes of the other temperature monitor for the comparison.) I would buy another if I needed a second one.I tested it from 4VDC to 28VDC and varied the power supply output rapidly by hand. It handled it without issue. I did not do high speed power input testing, though (but really that's a bit excessive for a product like this anyway).There are a few things I would mention to buyers of this device:1. The temperature probes have a fairly high thermal mass (they are large). This is not necessarily bad, but it means that they will not react very quickly to temperature changes. For an automotive application I don't think this is a bad thing - it is just an observation. This is why the product description mentions it working best in water (as in an aquarium, etc.).2. If you run the device at its maximum voltage (28V), it heats up after a few minutes. It draws 0.250W at 28V but only 0.032W at 4V. Basically it always draws 8-9mA. This is because the device uses a linear voltage regulator to condition the input power.Again, this isn't bad. It doesn't even get hot, just a little warm. Something to be aware of. Make sure the temperature probes are not close to the display module or it could raise the temperature you are measuring.3. I don't see any filtering circuitry on the power input. Watch out for possible transients on the input power supply. Use a good voltage or add external capacitance to the power supply input and a TVS diode if you have to use it in an environment with dirty power. It's easy and cheap to add this on if needed. For aquariums, 3D printers, that kind of thing, this isn't an issue.4. There isn't any reverse polarity protection on the power input. If you connect the power backwards by accident it could damage the device. This is listed in the product description but I want to make it very clear so others take care when powering it up. If you want to add reverse polarity protection to it, you can put a P-channel mosfet in series with the positive power input. Google "PFET transistor reverse polarity protection" for a simple circuit that accomplishes this.The temperature sensors are very accurate. This product is excellent for controlled environments. I would not want to plug it into my car's power without a power supply or extra protection in between because car alternators can generate transients. For 3D printers, product/DIY lab heat differential tests, aquariums, and similar applications where input power is controlled, it is a great product.Things I like about it:1. Mechanical design seems easy to use and durable2. Lens cover over LED displays makes it easy to read3. LED displays are nice and bright and look better than LCD4. Wide operating voltage is convenient5. Connectors for sensors and power instead of soldered directly (crimps were done well, too)6. Sensors are quite accurate (at least as good as advertised, if not better)7. Very wide temperature range (but will the microcontroller still work at -58F? Is the circuitry of the meter rated for industrial range, or is it only the temperature sensor? I don't know the answer to that)8. Product behaves well when voltage is changed by hand between 4-28V. No fluctuations in measurement or weird behavior. I don't have the test equipment to test rapid fluctuations or transients.The microcontroller is a NUVOTON MS51FB9AE. It actually has a 5-pin through-hole header on the PCB (see photos). For the hacking inclined, if you are familiar with 8051 and have the right debugger, you could probably re-flash this thing and make it do something else; for example, if you wanted a different kind of sensor or something attached.

So I know that the IS Icstation Digital Thermometer was meant for use with fish aquariums but as usual I have found other uses for it.First of all I was surprised at the accuracy of the unit and the tracking of the two probes. They were within .6 degrees (F) of each other. Again, very surprising for a device in this price range. The unit is well built and simple to set up and operate as there are no user controls or calibration procedures. The wide input voltage range (4-28 VDC) lends its self to well various power supply options. I used an old USB “Wall wart” that I had lying around. Although I have not yet used the complete temperature range of -58F~257F it is nice to know that such a wide spread is available.The winter season is beginning here and this past week I have seen temperatures down to 18 degrees (F). I figured that it was time to prepare my gas fired furnace for the long cold season. First of all if you are not qualified and trained to do any of the procedures I talk about here, DO NOT DO IT!I used the digital thermometer to check the temperature differential between the return air and output air of my furnace. After all, the difference temperature between the two included probes is what this device is all about, right? I read the installer’s manual included with the furnace and noted the stated temperature rise. Placing one probe in the return air duct and one in the plenum above the furnace I was able to set the burner regulator to the recommended specs. This procedure took less than 45 minutes to complete. This was a useful undertaking but I wanted to do more.My next endeavor was to check the temperatures of my refrigerator and freezer. They were close to what I had set on the control panel.Earlier in the week I headed out to the garage where I put one probe inside of the air cleaner of my 1932 Ford hot rod and the other outside of the engine compartment so as to measure the ambient air temperature. If you are into cars you know that engines like to feed on cool air. The outside temperature was mild (In the mid 70’s). I was surprised that driving down the road at around 40 MPH the intake air temperature was above 125 degrees (F).For my last test so far I checked the ambient air temperature VS the internal air temperature of my desktop gaming computer using different cooling fan combinations. This took quite a bit of time due to how long it took to change fan types and configurations but in the end I had a computer that ran cooler and quieter which was my goal.As I said in the beginning, this device was meant to be used with fish aquariums but I most always find a way to repurpose things, however I gave this one to my son who does have a fish tank. He told me that so far it is working great and has helped him adjust his heater placement and it’s temperature to make his fish smile???At this price point I think that this thermometer is worth having around just in case that YOU NEED IT!I wonder what uses others will find for this thermometer?I don’t think that I will be getting mine back so I am going to order another one. I recommend this product.

Primary problem, live view of potentiometer value based on ntc temp curve.I have a simulator system with 2 controllers, one allows me to check inputs, simulated by potentiometers, the other allows me to simulate use case scenarios of a AC, after processing through an ecu.The ecu interprets the potentiometer settings and reacts how it would if actually installed. However I can not simulate the response, and view the inputs at the same time, thus my interest in this product.With a potentiometer simulating the temperature of ntc sensor, I initially tried to reference a 10kohm @25c chart to find my temperature, however the values were inaccurate.Using this product it returns a code reading LLL. I assume its out of range.however out the box it work well, and is accurate. If you are inclined you can use most types of 10kohm@25C NTC probes, and extend the probe cables as needed, I believe you could use a Molex 2181120204 pigtail, and butt connectors to customize your device, as it should connect to any of the 3 inputs where you could change wire lengths as needed, I believe adding a substantial amount of length could however introduce some error in measurements as the resistance would change from the original calibration point.