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INKBIRD

INKBIRD INK-RD3

Battery radon monitor with an e-ink screen

  • Monitor
  • Battery
  • Screen
  • First reading in 24 hours
C-NRPP 2024/25 evaluation: Not includedSee the evidence
  • INKBIRD INK-RD3
  • INKBIRD INK-RD3, photo 2 of 6
  • INKBIRD INK-RD3, photo 3 of 6
  • INKBIRD INK-RD3, photo 4 of 6
  • INKBIRD INK-RD3, photo 5 of 6
  • INKBIRD INK-RD3, photo 6 of 6

Photos: INKBIRD

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  • PowerBattery
  • ReadingsScreen
  • First reading24 hours
  • C-NRPP 2024/25Not included
  • Every figure checked against the specifications INKBIRD publishes
  • Independent test results shown the same way for every product, unranked
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About this item

As INKBIRD states it

  • How it measures: Passive radon diffusion chamber with an alpha spectrometer sensor
  • First reading: Within 24 hours
  • Reading updates: 1 hour (updating the average of the previous hour); short-term average for the last day updated hourly, long-term average up to one year updated once a day
  • Display and app: Built-in display, no app
  • Power: Battery: 3 AAA alkaline batteries (LR03), included; battery life 2 years
  • Units: pCi/L or Bq/m³, selectable on the device

The INK-RD3 is INKBIRD's cordless radon monitor: a passive diffusion chamber with an alpha spectrometer sensor, a 1.54-inch e-ink screen showing a 1-day and a long-term average, a three-colour light and bar scale, and three AAA batteries that INKBIRD rates for 2 years. It has no app and no wireless connection. It was not included in C-NRPP's 2024/25 evaluation, so there is no independent result for it either way; two other INKBIRD radon monitors are on C-NRPP's not-approved list, both marked recalled.

What you get

INKBIRD lists the package as the radon monitor, three AAA batteries, a user manual and an operating needle, which is used to press the recessed MODE and RESET buttons. The batteries are LR03 alkaline cells, and the manual says to use only that type.

In the box and running costs

How it works

What it measures and how

The sensor, the sampling and the readings, then who has checked it

How it works

In our words, from the maker's documents

INKBIRD lists the detecting technology as a passive radon diffusion chamber and the sensor as an alpha spectrometer. Passive means room air reaches the chamber on its own, with no fan or pump, and the reading is made inside the monitor, with nothing sent to a laboratory. The manual gives the manufacture model as RN-300S alongside INKBIRD's own model number, INK-RD3.

After the battery tab is pulled, the screen shows "CALIBRATING" for less than a minute while the monitor runs a self-test, then "DATA COLLECTING" with up to six flashing bars counting down to the first result. INKBIRD says that phase typically lasts 24 hours. From then on the reading refreshes every hour, each time updating the average of the previous hour.

The e-ink screen shows two figures. The short-term average is the average for the last day, updated hourly. The long-term average covers the ongoing measurement, up to one year, and is updated once a day. A press of the MODE button shows how many days the monitor has been measuring since it was started or last reset. Those two averages and the day count are all the monitor shows.

Warnings are visual only. An LED at the top flashes every minute while the monitor is running, and INKBIRD describes the radon level indicator as an LED light and 3-colour bars: red for danger at 4 pCi/L (150 Bq/m³) and above, yellow for warning at 2.7 to 3.9 pCi/L (100 to 149 Bq/m³), and green below 2.7 pCi/L (100 Bq/m³). The manual describes no sound alarm. A low-battery icon appears when the batteries need changing.

INKBIRD publishes a measurement range of 0 to 500 pCi/L (0 to 9999 Bq/m³), with the units switchable between pCi/L and Bq/m³ using the supplied needle on the MODE button. It gives an operating range of 0 to 40°C at relative humidity below 85%, a size of 103 mm (D) by 33.3 mm (H), and a weight of 157 grams with batteries.

What the manufacturer says

INKBIRD's own statements, attributed

  • INKBIRD saysINKBIRD lists the accuracy and precision as typical at 5.4 pCi/L (200 Bq/m³): within 10% after 7 days and within 5% after 2 months.
  • INKBIRD saysINKBIRD states the three AAA batteries supplied last for 2 years.
  • INKBIRD saysINKBIRD describes the visual notifications as alerting you when radon concentration levels reach unhealthy levels.
  • INKBIRD saysINKBIRD describes the built-in alpha spectrometer sensor as giving accurate detection of airborne radon concentration.
  • INKBIRD saysINKBIRD says the monitor is suitable for a variety of indoor environments, including homes, schools and offices.

These are INKBIRD's own statements, attributed to it. They are not our findings, and we have not tested this product ourselves.

Independent evidence

C-NRPP 2024/25, recalls and studies

C-NRPP 2024/25
Not included in C-NRPP's 2024/25 evaluation

The Canadian National Radon Proficiency Program's 2024/25 comparison of consumer monitors did not include INKBIRD INK-RD3. That is a fact about which devices took part, not a finding about this one: no result from that program exists for it either way.

Recalls
No Health Canada recall or advisory names this device.
Peer-reviewed studies
We found no peer-reviewed comparison that names this model.
Notes
  • Two other INKBIRD radon monitors are on C-NRPP's not-approved list, the INKBIRD INK-RD2 and the INKBIRD Home Radon Meter, and C-NRPP marks both as recalled by Health Canada.
  • Health Canada recalled the InkBird Wifi Radon Detector model RD-2, labelled "Ink-RD2" (RA-77461, 2025). The INK-RD3 is a different model with its own model number: battery-powered, with an e-ink screen and no Wi-Fi.

C-NRPP is the Canadian National Radon Proficiency Program. Its 2024/25 results were published in May 2025.

Specifications

Specifications

Every figure as the maker states it

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The maker's figures

Type
Continuous monitor, battery (3 AAA), e-ink screen, LED and colour bars, no app
How it measures
Passive radon diffusion chamber with an alpha spectrometer sensor
First reading
Within 24 hours
Reading updates
1 hour (updating the average of the previous hour); short-term average for the last day updated hourly, long-term average up to one year updated once a day
Display and app
Built-in display, no app
Power
Battery: 3 AAA alkaline batteries (LR03), included; battery life 2 years
Units
pCi/L or Bq/m³, selectable on the device

What is in the box

INKBIRD lists the package as the radon monitor, three AAA batteries, a user manual and an operating needle, which is used to press the recessed MODE and RESET buttons. The batteries are LR03 alkaline cells, and the manual says to use only that type.

The manual gives a 1-year warranty against defects in components or workmanship, under which INKBIRD repairs or replaces a defective unit at its discretion and without charge. INKBIRD's product page shows the same 1-year warranty with a 30-day return. Its own store ships to most US states, from a US warehouse or its factory in China depending on stock.

What it costs to run

There is no lab fee, subscription or app. The running cost is batteries: three AAA alkaline cells, which INKBIRD rates for 2 years, replaced when the low-battery icon appears. INKBIRD's documents do not say whether changing batteries keeps or clears the stored averages, so that is not stated by the maker; the manual says only that a reset clears them.

INKBIRD publishes no calibration service, sensor lifespan or replacement schedule for the INK-RD3, so those are not stated by the maker. C-NRPP notes that consumer radon monitors cannot be professionally calibrated.

Fit and setup

Who it fits, and how to use it

The fit, then setup and placement as the guidance asks

Who it fits

Good fit if, and look elsewhere if

Good fit if

  • You want to read radon averages on the device itself, with no phone, app or account.
  • You want a cordless monitor that can sit anywhere, on three AAA batteries INKBIRD rates for 2 years.
  • You want a colour scale on the device that turns yellow from 2.7 pCi/L and red from 4 pCi/L.
  • You are comfortable writing readings down yourself, since the monitor keeps averages rather than a downloadable log.

Look elsewhere if

  • You want a monitor whose own model was graded in C-NRPP's 2024/25 evaluation; the INK-RD3 was not included.
  • You want hourly history, charts or alerts on your phone; the INK-RD3 has no app, Bluetooth or Wi-Fi.
  • You want an audible alarm; INKBIRD describes only a light and colour bars.
  • You need a result for a home sale; check what your state accepts before relying on any consumer monitor.

Setup and placement

4 steps

  1. INKBIRD's manual says to pull out the battery tab on the back to start the monitor, then leave it for about 24 hours while it collects data for its first result. Place it in living areas such as a bedroom or living room, in spots representative of the air breathed there, out of direct sunlight and moisture, at least 50 cm above the floor and at least 150 cm from the nearest door, window or vent, and do not move it during a measurement.
  2. If the screen shows an error with "SORRY", the manual says to press RESET, or take the batteries out, clean the contacts and put them back after more than 30 minutes, and to contact INKBIRD support if the message persists. To change units, hold MODE with the needle for more than a second, press once to choose, and hold again to confirm.
  3. EPA's general guidance for any home radon test is to measure on the lowest lived-in level of the home, in a room used regularly but not the kitchen or bathroom, at least 20 inches above the floor and away from drafts, high heat, high humidity and exterior walls. EPA says to fix the home at 4 pCi/L or more and to consider fixing between 2 and 4 pCi/L.
  4. C-NRPP's advice for any consumer monitor is to place it in a room occupied at least 4 hours a day, to test for a minimum of 3 months, preferably in the heating season, and to decide on the long-term average, following up with a long-term test if you have less than 91 days of data. On the INK-RD3 that figure is the long-term average on the screen, which runs until it is reset or reaches one year.

How C-NRPP says to use any consumer monitor

  • Leave it in place for at least three months, ideally through the heating season, when indoor radon tends to be highest.
  • Put it in a room someone uses for at least four hours a day.
  • Decide about fixing your home from the long-term average, not a single day or week.
  • If you can only run a monitor for less than 91 days, follow up with a long-term test.

For where any radon test or monitor should sit in a home, see where to place a radon test.

Compare

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The same three rows for each, and the one difference that matters

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Questions

Questions people ask

6 questions about the INKBIRD INK-RD3, answered

Asked about the INK-RD3

Is the INK-RD3 one of the INKBIRD monitors on C-NRPP's not-approved list?

No. C-NRPP's not-approved list has two INKBIRD rows, the INKBIRD INK-RD2 and the INKBIRD Home Radon Meter, and marks both as recalled by Health Canada. Health Canada's recall (RA-77461, 2025) names the InkBird Wifi Radon Detector model RD-2, labelled "Ink-RD2", after its Radiation Protection Bureau found that it did not measure radon levels correctly. The INK-RD3 is a different model with its own model number: battery-powered, with an e-ink screen and no Wi-Fi.

The INK-RD3 itself was not included in C-NRPP's 2024/25 evaluation, so there is no C-NRPP result for it either way.

Does the INK-RD3 have an alarm?

Not one you can hear. INKBIRD's warning is the LED light and colour bars on the device, which turn yellow from 2.7 pCi/L and red at 4 pCi/L. The manual describes no buzzer, and with no app there is no phone alert, so a high reading is only noticed by someone who looks at the monitor.

How long before it shows a radon reading?

About 24 hours. INKBIRD says the first result comes about a day after power-on, after a short self-test and a data collecting phase shown by flashing bars. The figure then refreshes every hour. A single day is a short-term number; the long-term average on the screen, built up over months, is the one to decide on.

Can I see past readings or export them?

Not as a history. The screen shows the last day's average and the long-term average for up to a year, plus the count of measuring days. There is no app, Bluetooth or Wi-Fi, and a reset clears all stored radon data, so INKBIRD's manual suggests writing readings down before resetting.

How accurate does INKBIRD say it is?

INKBIRD's figure is under 10% after 7 days and under 5% after 2 months, at a typical 5.4 pCi/L (200 Bq/m³). The manual does not describe the conditions behind it, and no independent program has published a result for the INK-RD3. Even by the maker's numbers the error narrows with time, one more reason to decide on the long-term average.

Can I put it in a basement or garage?

INKBIRD's two documents differ here. The product page calls the INK-RD3 ideal for garages, basements, cellars and living rooms. The manual's placement steps are narrower: living areas such as a bedroom or living room, in spots representative of the air breathed there, out of sunlight and moisture.

For a reading that reflects your exposure, EPA's advice points the same way as the manual: the lowest lived-in level of the home, in a room used regularly. A basement you live in fits that; a garage or an unused cellar is not a lived-in room.

What to do next

Updated October 8, 2026