Compare how you will read it
We compared the manufacturer’s published specifications, without testing either sensor. The pages now use the TempPro name and note that packaging may use an earlier brand name; retailers may still show ThermoPro. Match the model number and included features before buying.
| Feature | TP50 | TP55 |
|---|---|---|
| Body size | 79 × 66 × 24 mm | 110 × 85 × 25 mm |
| Backlight in specifications | No | Yes |
| Battery requirement | One AAA | Two AAA |
| High/low records | Listed | Listed |
| Remote phone reading | Not included | Not included |
Listing inconsistency: the TP50 page title advertises a backlit display while its specification table says “Backlight: No.” We use the table for this comparison, but recommend confirming the supplied version with the seller if that feature matters. We have not independently verified calibration or comparative accuracy.
Choose for placement, not a savings claim
Think about the distance from your usual viewing position to the shelf or wall. The compact option may be enough for a desk you pass frequently. A larger display can be more convenient when you want to check from farther away; a backlight may help in a dim room. Try measuring the available space before paying for a larger unit.
A monitor reports conditions; it does not automatically alter heating, cooling or ventilation. Buying one does not establish a saving. If you already have a readable, suitable sensor in the room, begin by using that information consistently.
Check whether you need a local display or a remote history. Neither of these models provides phone monitoring in the specifications reviewed. If your real task is checking an empty home remotely, neither answers it on its own.
A simple observation sheet before changing equipment
Use a small log with columns for date, time, temperature, relative humidity, direct sun and the appliance setting. Put the monitor in a representative room location, following its instructions. Avoid comparing a sunny windowsill with a shaded interior shelf as if they describe the same conditions.
For example, record the room before an afternoon cooling period and later at a consistent time. Note whether windows were open and whether cooking, laundry or occupancy changed. Repeat on more than one day before treating a pattern as typical. These are observations of your room, not a controlled product test.
If you change the curtain position or cooling schedule, change one factor at a time where practical and keep the monitoring location consistent. A different outdoor temperature can overwhelm the effect you were trying to observe. An apparent improvement on one cooler day is not proof of a particular percentage saving.
Connect comfort readings to an energy estimate
Temperature and humidity readings do not give you kWh. To evaluate a dehumidifier’s electricity cost, use representative energy measurements or clearly labeled power assumptions in the running-cost calculator. Read our dehumidifier cost guide before multiplying the rated power by every hour of the day.
Keep the two questions separate: did the room conditions change, and how much electricity did the appliance use? Recording both makes a decision more useful than focusing on the monitor’s comfort symbol alone. A household display is not a diagnosis of building moisture or a substitute for investigating a leak.
Our decision rule
Choose the smaller TP50 when nearby readings meet your need. Consider the TP55 when display size and illumination matter more. Confirm the retailer’s exact variant, especially the TP50 lighting discrepancy, and check the current return terms.
The affiliate option below is the TP50; the manufacturer’s TP55 page remains available in Sources so you can compare both. We have not assigned test scores, claimed that one sensor is more accurate, or ranked them by commission.
Choose your next step
Continue with the question that matches your next decision:
Shopping options for this guide
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TempPro TP50 indoor thermometer and humidity monitor
Track room temperature and relative humidity when comparing cooling settings. The TP50 shows both readings and records high and low values; it does not measure electricity use.
Before buying: The listing may ship ThermoPro or TempPro branding. The manufacturer page has conflicting backlight information; confirm the supplied version and calibration features with the seller. Follow placement instructions and allow readings to settle. This is not an electricity meter.
View TempPro TP50 indoor thermometer and humidity monitor at Amazon.com (opens in a new tab)These are shopping options, not hands-on test results. Check the retailer for current specifications, price and availability.
Sources & further reading
Numerical examples are illustrative unless explicitly described as measured. This guide does not claim hands-on product testing. Read the methodology and editorial disclosure.