In the early 1990s FEMA procured and issued this version of the Army Radiac set AN/VDR-2 for Civil Defense radiological monitoring before they canceled their radiological instrument program in the 1990s. The FEMA CD V-718 unit is exactly the same as the Army AN/VDR-2 unit but is painted yellow instead of olive drab and reads out in milliRoentgens and Roentgens instead of Grays. The manual with the set is a military style manual, is dated 1994 and has FEMA on the front cover.
It's interesting to note that it was assigned a "CD V" number and painted the same yellow color as the old Civil Defense instruments and that after almost 30 years since the Civil Defense era meters were issued FEMA seems to have still been following the same standard for identification of Civil Defense instruments. It's numbering continues in line right after the CD V-717. The CD V-718 doesn't have a radioactive check source or an audio output. There is an alarm "beeper" built in for the audio alarm function and the unit can also be set to emit low level "clicks" by the alarm upon detection of radiation like a standard geiger counter. The audio level of the clicks is very low so they can only be heard in very quiet surroundings.A super-huge thanks goes out to Mike S. for this instrument!
This is the front panel of the CD V-718. The digital LCD display is large, easy to read and has a backlight for reading in the dark. Round dark spots with Dose and Rate under them are the visual red alarm lights. All control switches are in a row at the bottom of the panel. Unit is indicating background radiation in this photo. The control switches are (from left to right) Power switch. Clr/Test switch (used to start operating test and with other buttons to perform various functions), Dose Per Hr switch (used with other buttons to, set dose rate alarm, display dose rate alarm set point and clear accumulated dose) Accumulated Dose switch (displays accumulated dose when pressed and with other buttons to perform various functions see photo below) Attenuation switch(press to display dose external to vehicle when vehicle mounted. Used with clear/test switch to display attenuation factor when the instrument is installed in a military vehicle and also used when turning on power to enable audio click function). Light on/off switch. Alarm Audio/Off/Visual selector switch. Click on the photo to see a larger version.
Here is a view of the rear of the unit. The Battery access cover has the "Warning" label on it. The unit operates on 3-9 Volt batteries. The battery compartment cover is heavily gasketed and is held in place with knurled thumbscrews. The heavy duty coiled probe cord has a connector only on the probe end and feeds into the back of the case without a connector. The small capped connector next to battery compartment is for connecting to a vehicles power. The manual has a list of military vehicles and their attenuation factors that the instrument adjusts radiation readings for when the unit is installed into a vehicle.
Here are the ID labels located on the top of the unit and probe. The bump on top of probe is the housing for the high range GM tube the low range tube is in probe housing. See photo below for shot of probe front.
Here's a close-up of the end of the probe. Probe end cover opens for Beta radiation monitoring. Thin end window looks like mylar or similar material to me. The manual has a note that the window can be easily ruptured by sharp objects.
Here's the accumulated dose display. Just under half a mR. The dose can be reset by pushing the Clr/Test button while holding the Accum Dose button.
I was messing around with the CD V-718 and I thought I would compare it to the good old CD V-700. I have an old World War II vintage Turn & Bank Indicator aircraft instrument with a radium dial that puts off about 10mR/hr of gamma radiation which I used as my source. Check out the photos above to see the results of the comparison. The photo on the left shows the indicator sitting on top of the CD V-718 probe and the meter reading 9.6mR/hr. The photo on the right shows the indicator right next to the CD V-700 probe and with the CD V-700 set on the x100 scale the reading is 10mR/hr. Pretty close. I got a little bit lower reading a couple of years later when I made the video for YouTube. Maybe I just had the radium dial in a little different postion. See below.
The CD V-718 case is well padded and rugged with military belt latches on the side. The case has a heavy strap as well. There is a viewing window on the top that allows the display to be read with the top flap closed. The background reading is a bit high in this photo because my Turn & Bank Indicator that I used in the above photos was sitting on the table about 3 feet away from the CD V-718.