The reasons why you want to build a KFM
(Kearny Fallout Meter)

1. It will accurately detect radiation so you can perform radiological defense.

2. It doesn't have to be calibrated like more expensive models
        (so you know that it is working).

3. It doesn't require batteries - which you might not be able to get.

4. It has no electronics and won't be affected by EMP.

5. It is very inexpensive.

6. MOST IMPORTANTLY - If you have and can make these at the time of emergency they will establish you as a person of value to be supported and protected. You will be able to trade them for security and other essentials.

Ark Two Resources for How to Build a KFM

It will take you about 8 hours to learn to build the first unit - no matter how many days or weeks that you spread the time over.


Day 1 - How long does it take you to make a decision that you are going to build one?
Day 2 - How long does it take you to find a friend to join you in the effort?
Day 3 - About an hour and a half to two hours entertainment
               for you and your friend to look at the Day 3 videos.
Day 4 - About two hours to get together the tools and materials.
Day 5 - About four hours to actually build the first unit.
Day 6 - About two hours to build a second unit.

      (If set up you can then build about one per hour - and many more
      if you use division of labor with other people).

Day One
Deciding to build a KFM (Kearny Fallout Meter) radiation detector

Day Two
Finding someone capable of working with you

Day Three
An hour and a half to two hours
watching together the following 13 general items
about building the KFM
(Item 01)
Part 1 - Ark Two General Introduction to Inexpensive Detectors
10 minutes

(Item 02)
Part 2 - Ark Two about problems building the KFM
10 minutes
      (with thanks for direct assistance from Steve Jones
      referenced by Cresson Kearny as a contributor to the KFM design)
(Item 03)
Part 3 - Ark Two Detailed Explanation
on making proper threads for the KFM
10 minutes

(Item 04)
a separate authenticating source about the value of this device
(skim read for 10 minutes or less)

(Item 05)
by Cryptic Cricket
showing an excellent completed unit -
with a superb viewing stand of his design
An excellent 2 and half minute video

The original KFM design was by Cresson Kearny (with whom I have spoken personally) and the following videos are his own explanation - about the meter's history and construction. (Cresson passed on in 2003).

(Item 06 - Not absolutely necessary to watch)
Cresson Kearny Part 1
( shows about some different types of meters)
(9 minutes)

(Item 07 - Not absolutely necessary to watch)
Cresson Kearny Part 2
Explains about why he developed the Kearny Fallout Meter (KFM)
(15 minutes)

      (Explains the advantage of the KFM over expensive models - in that you can be sure the KFM is working and correctly calibrated - whereas you can't be sure even with the other most expensive types.)
(Item 08 - Not absolutely necessary to watch)
Cresson Kearny Part 3
(15 minutes)

      (From 5:50 forward he explains about making the drying material -
      and this is the best explanation of that - which I know of.)

(Item 09 - IMPORTANT to watch)
Part 1 of 12 year old girl's demo -
(6 minutes)

(Item 10 - IMPORTANT to watch)
Part 2 of 12 year old girl's demo -
(3 minutes)

(Item 11 - IMPORTANT to watch)
Part 3 of 12 year old girl's demo -
(5 minutes)

(Item 12 - IMPORTANT to watch)

Part 4 of 12 year old girl's demo -
(3 minutes)

(Item 13 - IMPORTANT to watch)
Part 5 of 12 year old girl's demo -
(3 minutes)

Day Four
Gathering the tools and materials
(Print this off and use it as a checklist)

Tools: (No electricity or power tools required)
    1. An inside work area - table area about 4 feet long and 3 feet deep.

    2. Light - daylight through a window will do.

    3. Flat piece of cardboard (maybe a flattened box) to use as a soft work surface for cutting and to protect the table.

    4. Some brown (or any color) paper (to lay on top of the cardboard to cushion the cutting.

    5. Box cutter or sharp utility knife

    6. Scissors capable of cutting paper and thin tin

    7. Marking pen - with narrow point

    8. Small cellophane tape dispenser

    9. One foot (or longer) ruler

    10. A can or container to heat the drying material in.

    11. Some way of providing heat.

    12. A bucket for creating a dry operating area.

    13. A tightly sealing jar for storing the drying material in.

    14. Tightly sealing large jar or other airtight container for storing the completed unit in.

    15. A pair of pliers for breaking up the gypsum can be useful but not absolutely necessary.

    16. A large nail for use as a punch

    17. A hammer to use with the nail to punch holes in the cans.

    18. A block of wood to fit inside the can while punching the holes.

    19. A flashlight (preferably hand wound - or with batteries) for using the unit at night.

    20. A battery operated or mechanically wound watch or other timing device that provides time in seconds.

    21. A pencil or pen

    22. A notebook for keeping record of the readings.


    1. Can cover pattern

    2. Can wrap pattern

These first two items are the most difficult to obtain. You can copy them out of Kearny's book or from such other sources as you may have OR you can use a computer printer and print them from

Can Cover Pattern png

Can Wrap Pattern png

Measure the black rectangle - if it is not EXACTLY 3 inches long then take your image into a photo editing program and lengthen or shorten the width of the image as necessary. Be sure to keep the height to width proportion the same.

Do this step repeatedly until you get the black rectangle to being EXACTLY 3 inches long on BOTH of the patterns. You can then photocopy your image and measure the rectangle on the photocopy. AGAIN if the rectangle is not exactly 3 inches long - you will need to repeat the process by either adjusting the photocopier or the original image.

Once you are getting correct copies you may as well make a number of them. Say two large manila envelopes with 100 of each. These are the critical factor that you might not be able to get later.

    3. Cans of the proper size. Soft drink cans are good. Once you cut them down be sure to wash them out good and dry them.

    4. Clear cellophane - like used in the kitchen for wrapping food

    5. Aluminum foil - standard (not heavy duty).

    6. A thin clear garment bag off of clothes returned from the dry cleaners.

    7. Clear cellophane tape like used for mending a page in a book (to go in the tape dispenser mentioned in the tools).

    8. Non-conductive electrician's tape (usually black).

    9. Band aids - this is for the unit. (We are not expecting you to cut yourself)

    10. Copper wire - preferably solid, about the diameter of a pencil led or a little thicker. If it doesn't already have an insulating covering sheath, you will make one for it.

    11. A piece of strong clear plastic to generate the electric spark. Try several out to find one you like.

    12. A piece of wool (an old wool sock or whatever) to rub on the plastic.

    (Another way instead of using 11 and 12 for charging the unit is to quickly pull off a piece of tape from a large roll of cellophane tape.)

    13. Some Gypsum wallboard (sheetrock) to make the drying material. (There are drying gels that can be useful also - but study the literature and be judicious about what you select if you decide to use them).

    14. Heavy mill plastic sheet for covering the charging bucket.

    15. Duct tape for sealing the plastic sheet on to the top of the charging bucket.

    16. Rubber bands (for sealing the top of the unit) or string, and thread for the limiting threads inside the unit.

    17. These lists always include a toothpick or maybe a piece of wood to make a splinter off of. Sometimes, for somethings you may need to be a bit creative.

    18. Lots of patience and a patient friend.

It will take you a couple of hours to gather all these tools and materials. This will have been a good days effort on this project - and will be all ready to go without interuption or frustration on the assembly day.

Day Five
Assembling the unit

As shown in both the Kearny Video and the video by the 12 year old girl - read outloud step by step what it is that you are to do. You have the advantage of also being able to step through the videos by the 12 year old girl. Do one step and then proceed on to the next.

The full instructions, which you need to print out, are available at:

Cresson Kearney's Instructions from Nuclear War Survival Skills

Thousands of people have been successful but you will probably never meet another one unless you train them. I hope you will train many because it may become a very rare and valuable skill that can save many lives.

Day Six
Using the KFM

Once you have built your unit you want to study about how to use it to be sure you can get accurate readings. More than that you need to study the significance of various levels of readings and the types of radiation defense that you can take. I have a number of videos in that regards at:
Ark Two Videos

and there is a great amount of materials available throughout our web site.