Model 951
When I calibrate (i.e. turn on) my nukeALERT and then go on patrol, there are several spots where it always goes off, even though there is no radiation source visible. Is there a problem and can the nukeALERT be adjusted to stop doing this? If you turn the nukeALERT on in a quiet radiation area and then walk by higher-levels of natural radiation, the nukeALERT will detect the increase in natural radiation background. High-level natural radiation can be found near some large rocks, or in some buildings that use stone (like granite), or near some ceramics that use powdered stone. Increased elevation also increases natural radiation (large increases such as mountains). The nukeALERT is functioning normally in detecting this increase in natural levels of radiation. The nukeALERT can be adjusted to raise the background sensitivity level so that it does not alarm on natural levels of radiation. See “Adjusting my nukeALERT’s sensitivity” also. (Back)
Why does the nukeALERT "recalibrate" as I travel to and from work? When the nukeALERT is turned on, it calibrates itself to the natural radiation background. When the nukeALERT notices the background has reduced, it will recalibrate itself to improve the sensitivity. When you are going to work, at some point the nukeALERT detects that it’s in a lower natural background environment and recalibrates itself to ensure maximum detector sensitivity. You often see a reduced background count and a recalibration if you take the nukeALERT into a car or truck. (Back)
Should I "recalibrate" the nukeALERT as I travel around the country and experience "1’s & 2’s" in some locations? You can detect some 1’s and 2’s from natural sources as you roam with the nukeALERT. The nukeALERT is performing normally and does not need recalibrating. However, if it becomes distracting you can change the internal background switch to raise the low-level detect to the point where it will not trip on natural levels. See “Adjusting my nukeALERT’s sensitivity” also. (Back)
Will the nukeALERT still be sensitive if I travel from an area of high natural radiation to an area of low radiation? Do I need to recalibrate? What about the other way around, low to high? The nukeALERT will still be sensitive if you travel from an area of high natural radiation to low. If the change in levels is significant, the nukeALERT will automatically recalibrate itself to maintain maximum sensitivity. If you travel from a low radiation area to a high, the nukeALERT will probably give you “1”s and “2” periodically. Simply turn the nukeALERT off and on again to recalibrate, and the “1”s and “2” due to natural background will go away. If you go from low to high frequently, you can also use the adjustment switch in the nukeALERT raise the detection floor so that it doesn’t alarm at those small levels. See “Adjusting my nukeALERT’s sensitivity” also. (Back)
Is there any way to permanently set the sensitivity higher to adjust for constant high background levels, (around an X-Ray machine, etc). The nukeALERT contains an Adjustment Switch that allows you to manually adjust the lowest level sensitivity of the detector. This should not be casually adjusted, since it reduces the highest sensitivity of the detector. Usually, this switch is adjusted at the factory or by your tech support. And you want to keep track of which nukeALERT’s have which settings; otherwise, you could have 50 nukeALERT’s, each with different sensitivity settings. (Back)
If I prefer a particular setting on the adjustment switch, do I have to change all the nukeALERT’s or can BNC make the adjustment before delivery? BNC will adjust the nukeALERT’s to your desired level before delivery. We can also ship you a nukeALERT in advance and allow you to experiment and determine if any adjustment to the sensitivity level is desired. (Back)
Are there any ongoing maintenance procedures or parts needed for the nukeALERT? No. (Back)
Will changing the internal background switch affect all levels of sensitivity of the nukeALERT? No, it only changes the lower levels of detection. Significant amounts of radioactive material will still be detected at the same level. (Back)
Can the nukeALERT tell me when radiation levels are hazardously high? Yes. The nukeALERT displays an alarm level of ‘1’ through ‘9’. This value tells you the number of photons being measured at the detector. The point where the displayed alarm goes from an ‘8’ to a ‘9’ is equivalent to a dose rate of approximately .442 mRems/hour. To determine whether the detected radiation source is at a hazardous level, you need to find the range from the source where the nukeALERT display switches from an ‘8’ to a ‘9’. Once the range is known, it is easy to determine an approximate dose rate on a reference card. (Back)
How do I adjust my nukeALERT’s sensitivity? (refer to switch location on page 6 of the manual) We recommend that you have your staff technician perform the adjustment, and note the level of adjustment for the unit. After the first adjustment, the technician should be able to adjust a unit in two minutes. Tools: A good, directable light source, A 2 mm blade screwdriver, about 4” long (standard computer/jeweler screwdriver), A small phillips screwdriver, Procedure: 1) Turn off the nukeALERT. 2) Open the battery door with the small phillips screwdriver. 3) Remove the batteries 4) Look between the two battery stops at the back of the battery compartment and you’ll see a small 16-position switch. You’ll need a bright light to see down that far. 5) With the 2 mm screwdriver, turn the switch clockwise to raise the value. 6) Log the switch setting for that serial number. 7) Replace the batteries and close the door. 8) Turn the unit on and use it normally. We recommend adjusting the switch in 2-position steps and then using it for a while. If it still is not at the desired level of sensitivity, adjust it further. Once a single nukeALERT is configured and tested for an area, the other nukeALERT’s can be set to the same level. (Back)
How does the 16 point calibration switch work? The purpose of this adjustment and switch is to allow adjustment of the background level radiation value if the user is operating in an environment where the backgroung radiation swings back and forth frequently (such as in close proximity to an operating X-ray machine). This switch adjusts the "1" to "9" scale so that an operator in those environments do not constantly get false alarms. For example, guards on roving patrols who regularly walk by granite or marble which may trigger the unit to alarm may find low level sensitivity settings annoying. Position "0" on the internal switch is the most sensitive. It adds no bias to the algorithm. Units are always sent out set to "0" unless the customer has ordered it with a bias. Position F (16th switch position) adds the most bias. The 16-position switch is located inside the back of the battery compartment of the nukeALERT and can be adjusted with a long handheld screwdriver. The majority of users will not require adjustment of this switch. This switch should only be adjusted by an informed operator. If the switch level is set too high, it will desensitize the nukeALERT and potentially allow low-level radiation sources through that would be detected under normal operation. (Back)
