Review on 🌡️ Icstation Digital Thermometer: Car Auto Temperature Gauge Sensor with Dual Display and Waterproof Probes for Aquariums & Vehicles by Heidi Ward

I am happy with this product and think I could put it to good use. I compared the readings to my current precision temperature monitor and the results are within +/- 0.5 degrees Fahrenheit (maybe better). (There is a photo showing how I connected the probes from another temperature monitor for comparison.) I would buy another if I needed a second one. I tested it from 4VDC to 28VDC and quickly changed the output voltage by hand. He got through it with no problems. However, I didn't do any high-speed power consumption tests (but it's actually a bit overkill for such a product). There are a few things I would like to mention to buyers of this device: 1. Temperature sensors have quite a large thermal mass (large dimensions). That's not necessarily a bad thing, but it does mean they don't respond to temperature changes very quickly. For an automotive application, I don't think that's a bad thing - it's just an observation. This is why the product description mentions that it works best in water (e.g. an aquarium, etc.).2. If you operate the device with maximum voltage (28 V), it will heat 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 regulate the input power. This is not bad either. It doesn't even get hot, just a little warmer. Something to be aware of. Make sure the temperature sensors are not close to the display module, otherwise the measured temperature may increase.3. I don't see any filter circuit on the power input. Be aware of possible transients on the input power supply. Use a good voltage or add external capacitance to the power supply input and TVS diode if you need to use it in a dirty power supply environment. It's easy and cheap to add when needed. This is not a problem for aquariums, 3D printers and the like.4. There is no reverse polarity protection on the power input. If you accidentally connect the power supply in reverse direction, it may damage the device. This is stated in the product description but I want to make it very clear so others will take care to include it. If you want to add reverse polarity protection, you can put a P-channel MOSFET in series with the positive power input. Google "PFET transistor reverse polarity protection" to find a simple circuit that implements this. The temperature sensors are very accurate. This product is excellent for controlled environments. I wouldn't want to connect it to my car's mains without a power supply or additional protection in between, as car alternators can generate transients. It is a great product for 3D printers, product/DIY lab testing, aquarium and similar applications where power consumption is controlled. What I like about it: 1. The mechanical design seems easy to use and durable2. Lens cap over LED displays makes reading easier3. The LED displays are nice and bright and look better than the LCD4. Wide operating voltage is convenient 5. Plugs for sensors and power instead of direct soldering (crimps were done well too)6. The sensors are fairly accurate (at least as good as advertised, if not better)7. Very wide temperature range (but does the microcontroller work at -58F? Is the measurement circuit designed for industrial use or is it just a temperature sensor? I don't know the answer to this question)8. The product behaves well when manually changing the voltage in the range of 4-28V. No fluctuations in the measurements or strange behavior. I don't have any test equipment to test fast oscillations or transients. Microcontroller - NUVOTON MS51FB9AE. It actually has a 5 pin through hole connector on the board (see photo). For those who are prone to hacking, if you're familiar with the 8051 and have the right debugger, you could probably reflash the thing and have it do something else; for example if you need a different type of sensor or something connected.