Step 1
Start with the upper right switch on STANDBY and the knob at OFF. Then turn the knob to 19.99, which will start a 50 second warm-up. During the warm-up, all three decimal points will be black. After warm-up, only one decimal point will remain, then push the right switch down to RE-ZERO and hold there at least five seconds. The display should now read between 0.02 (positive) and -0.02 (negative) and it should be stable for at least five seconds. If the display is not stable, RE-ZERO again.
If the wind is blowing and air is being forced through the Ion Counter, the sensor will collect ions, thus producing a non-zero signal. Subsequently, if you push the switch down to RE-ZERO, the new "zero" will not be accurate. In windy conditions you must shield the front with your hand and the back with your body and wait until the display becomes stable, then RE-ZERO again. Alternatively, you can balance the left switch (POLARITY) in the center position (neither + nor -), wait for the display to become stable, then RE-ZERO. This method will produce a more accurate "zero" in turbulent conditions, though you will have to wait longer before taking measurements, since you will need to switch away from this neutral position to either + or -, which is an additional step.
Step 2
To take a measurement, make sure POLARITY is set either + or - and hold the Ion Counter at arm's length or set it down. Set the switch to MEASURE, which will turn on the fan and make all three decimal points visible for about 20 seconds. After 20 seconds, only the center decimal point will remain. When switching to MEASURE, the display may go slightly negative, even when POLARITY is on +, or vice-versa. Within 20 seconds, this transient will settle and the counter will read the correct ion count, and will continue to be correct even as you move the counter through the area you're testing. For fastest, most accurate readings, measure an entire area on a single polarity, then reverse the polarity and re-measure the entire area. (This is as opposed to measuring + then immediately switching to - at each point in a room).
The ion counter works best if connected to ground or briefly touched to a grounded object before measurement starts. To do this, touch your finger on the center screw in a wall switch plate or wall outlet while holding the counter, or touch metal plumbing or the ground itself. If the ion counter has not been grounded, it may carry a significant static charge. This charge will either repel or attract ions, which will distort the readings. Note that all of the black surface of the ion counter, including the rubber feet, is electrically conductive. A ground cord, 20 feet in length, is included.
The ground cord can be attached (clipped on) to the back side of the Ion Counter. Connect the alligator clip (at the other end) to earth ground.
Holding the counter at arm's length is important if you are wearing synthetic fiber clothing. Synthetic clothing becomes charged and upsets the ion count. In fact, any strongly charged object in proximity to the counter will reduce the apparent ion count. In typical electric fields near synthetic fabric, negative ions are repelled at a speed of around 3 to 30 cm/sec (about 1-12 inches/sec). Positive ions are similarly attracted to the fabric. If the conductive outer case is highly charged + or - , it will either repel or absorb ions, so that in either case, the counter will not provide accurate readings.
Step 3
Now the Ion Counter is ready to take measurements and will display in units of 1000 ions per cubic centimeter, so multiply the display by 1000. For example, -0.28 = 280 negative ions/cm3. The air is sampled at the slot in the top of the Ion Counter. Hold the Ion Counter in one place for at least 10 seconds on MEASURE until the reading is stable, in order to acquire an accurate reading.
To determine a trend (whether the number of ions is greater or less as you move to a new area), simply observe whether the display increases or decreases as you move the counter through various areas. An ion "hot spot" or a depleted area will be apparent almost immediately. If you see a sudden increase or decrease in the ion count, hold the counter still for at least 10 seconds for a correct new reading. Ion concentration may significantly vary depending on the time of the day and the location.
Step 4
You can switch POLARITY at any time. This switch determines whether + or - ions are detected. After switching, the three decimal points will go black for approximately 30 seconds and the fan will turn off, then back on by itself. You do not need to RE-ZERO. Note that when the fan turns itself on, the three decimal points will remain on for an additional 20 seconds, as in Step 2.
Most readings can be done in the most sensitive range (19.99). If the scale indicates over range (1 ... or -1 ...), switch to 199.9 or 1999. You must RE-ZERO after you switch range (this will be obvious). To RE-ZERO, first switch to STANDBY and wait about 20 seconds for the display to stabilize.
Step 5
RE-ZERO about every five minutes (or more often if the temperature changes rapidly). To do this, switch to STANDBY and wait about 20 seconds until the display stops changing. If a breeze is blowing, shield the Ion Counter during this 20 seconds, or switch POLARITY to neutral as in Step1 above. Then, once the display becomes stable (doesn't change by more than 0.02 in five seconds) hold the switch at RE-ZERO for at least three seconds.
Step 6
When about 15 minutes of battery life remains, LO BAT indicator will come on at the left side of the liquid crystal display, most likely when the switch is turned to MEASURE and the fan is running. The LO BAT message and the colon symbol will fade out after about one minute; though as long as the batteries are low, it will display again every time the switch is changed from STANDBY to MEASURE or back again. When the batteries run low, readings can become unstable. After heavy continuous use, LO BAT may come on prematurely. If this occurs, just turn the switch to OFF for a few hours so the batteries can rest, which will prolong the battery life.
MEASURE requires about five times more battery power than STANDBY since MEASURE turns on the fan, so keep the switch on STANDBY when not taking measurements. The fan is inhibited from running during warm-up and polarity change, even when the switch is on MEASURE. When turning OFF, the right switch can be set on either MEASURE or STANDBY.
The Ion Counter requires two 9 volt batteries. To replace them, unscrew the four screws on the back. Alkaline batteries will last about three times longer than regular batteries. NiCad rechargeables also work, though you will need to use the 8.4 volt kind, not the 7.2 volt variety.
Maintenance
Use only water to clean the outside of the ion counter. Solvents may remove the special conductive coating!
The plastic wind guard (black "handle" on top) is a conductive electrostatic shield, though it can be removed to clean the metal plates inside. The plates only need cleaning if a piece of dust or lint makes a bridge between the center plate and the inside of the plate enclosure as shown.
This is not a common occurence.
Normally, when you reverse the POLARITY switch while on STANDBY, the display should settle back down to near zero after 30 seconds. If a dust bridge is present however, the display will not settle near zero within 30 seconds after you reverse the polarity switch.
Instead, it will settle on +/- 0.30 or higher.
For example, if the display reads -0.01 on STANDBY with the polarity switch at - , but after switching to + (and then waiting 30 seconds on STANDBY), it reads 0.35, it means that a piece of lint or other material (5 mm or longer) is forming a conductive path or bridge. To clean, snap out the wind guard and blow air into the slot, or clear the space inside with a strip of paper at least 10 cm (4") long to dislodge the material forming a bridge in the gap.
The counter will work without the wind guard in place, though the reading will be too high if wind is blowing toward the top, and too low if wind is blowing in the opposite direction. Also, without the electrostatic shielding of the wind guard, the counter could read too high or too low while being moved toward or away from a highly charged object. However, even if the wind guard is not in place, the counter will read correctly after being held motionless about 20 seconds, even if in proximity to a charged object.
It is possible that a small piece of lint or string can interfere with the motion of the fan. Always check that the fan comes on when it is supposed to, and if not, push it with your finger, or blow on it to start. The fan is very low-force and cannot hurt your finger. Check for any material that may interfere with the fan motion, and remove any foreign material(s). The fan should operate whenever the counter is on and the right switch is on MEASURE, except during the first 50 seconds after the unit is turned on, or during the first 30 seconds after the POLARITY is reversed.
Specifications
The Air ion Counter pulls air (or any other gas with ions present) through a parallel plate assembly. Outer two plates are held at polarization potential (+ or -). Center is the linear detector plate. Air gap is 4mm and polarization field is 1000 V/m.
Air flow: 200 cm3/sec (linear speed: 40 cm/sec)
Ion collection efficiency: 65%
Input resistance: 5 x 1010 Ohms
Dynamic range: 10 ions/cm3 (corresponds to 10 microVolts at detector plate) to 2 million ions/cm3 (corresponds to 2 Volts at detector plate)
Settling time: approximately 10 seconds
Noise level (10 seconds averaged): 10 ions/cm3
Accuracy: + / - 25% for fast ions (mobility greater than 8 x 10-5 m/s per V/m - which are the most numerous ions. The Ion Counter is less sensitive to "slow" ions such as charged pieces of dust)
Batteries: two 9-Volt standard or alkaline Battery life: A Standard heavy duty will last about 10 hours on STANDBY, or 2 hours on MEASURE. Alkaline; 30 hours on STANDBY, or 6 hours on MEASURE. LO BAT indicator comes on at 7.5 Volts (for each battery, or total 15 Volts), which indicates 10 to 30 minutes of MEASURE time remain.
Battery drain: 7 mA on STANDBY, 30 mA on MEASURE. Fails at 7.5 V/battery. Ion Selectivity (crosstalk): 20x Sensitivity with POLARITY switch in center position (neither + nor - ): 1/10 of normal, but adds together + and - ions. (Example: 600 + and 200 - will read 1/10 of 600 minus 200, or 40 ions/cm3).
Warranty: Two years
Made in USA.
Notes
1. If ion concentration is less than 100 ("0.10"), a longer STANDBY settling time should be used before RE-ZERO. In this case, watch the display until it stops drifting (about 30 seconds), and then RE-ZERO. Also, the display will take longer to reach final value when set on MEASURE if the ion concentration is very low.
2. If the Ion Counter is at the same temperature as the surroundings, the "ZERO" will be very stable. To reach temperature equilibrium, leave the Ion Counter OFF at least 30 minutes in the environment that will be measured. If outside, minimize its exposure to direct sunlight (which will make it hotter than the environment).
3. You can set the polarity on "neutral" (neither + nor -) by balancing the POLARITY switch in the center position. Then the sign of the display and its magnitude will tell you which type of ion predominates in the air, and its approximate concentration (although the actual reading will only be about 1/10 the true sum of the +/- ion concentrations).
When switching back to + or - afterward, allow about 30 seconds for the display to settle.
4. "Crosstalk" refers to ion polarity selectivity and is approximately 20x, which indicates, for example, that if there is a very high positive ion concentration, the display may read positive even when switched to negative. With this selectivity, 1000 positive ions and 0.0 negative ions per cubic centimeter will lead to a reading of +1000 when POLARITY is on + , and +50 (instead of 0.0) when POLARITY is set on -. If the display shows that one polarity of ions is more than five times as numerous as the other, a more accurate reading will result if you subtract 1/20 of the high number from the low. In the case above, 50 minus 1/20 of 1000 = 0.0 negative ions.
5. If you are measuring while walking, hold the Ion Counter vertical and at arm's length, which will make the moving air perpendicular to the air flow move through the Ion Counter. In windy conditions, hold it (or set it down) so it is vertical or at least perpendicular to the wind direction. If changing conditions require that it is sometimes parallel to the wind direction, have the air flow into the top (as opposed to into the bottom or fan side). This procedure will assure the most accurate readings. When air is rapidly flowing into the top, the Ion Counter will read slightly high, though if air is rapidly flowing into the fan side, it may read very low.
6. You are acquiring charge if you are exposed to the output of an ionizer or simply walking on a carpet. This may attract or repel ions, and it can even create + ions, since your highly negative charge can pull + ions out of neutral air. The conductive black outer casing of the Ion Counter will be at the same voltage as you are while you are holding it. It too may attract or repel ions. When walking on a carpet, the best accuracy is obtained if you do not wear plastic-soled shoes. Shoes which do not cause you to be "shocked" when you touch a grounded object are acceptable.
While measuring, touch a grounded object frequently to avoid too much buildup of charge. Also, you can set the Ion Counter on a glass tray or on a sheet of glass. (Plastic will not work well because it acquires a charge.) Hold the glass rather than the Ion Counter while walking and touch the Ion Counter to ground just before starting measurements. You can also use the ground clamp as long as the other end of the cable is connected to at least a weakly-grounded object. You can determine if the ground is acceptable since an acceptable ground will not let you build up charge, or get "shocked" when touching another grounded object.
7. Holding the counter near any alpha particle source (Uranium, Thorium, etc.) will produce very high ion readings, especially +. This Ion Counter can therefore directly be used in place of a Geiger Counter. Turn the switch to STANDBY and polarity to +. Remove the wind guard and hold the top of the Ion Counter close to the test source of possible radioactivity. If 0.l microCurie of 5 to 8 MeV alpha (Uranium, Thorium, Radium) is entering the top hole, the display will read 250,000 ions/cm3 ("250" on the 1999 scale). These alpha particles can only travel through about 5 cm (2") of air, so hold the top of the counter very near the suspected source. The display is proportional to the radioactivity present.
Neutrons can also be detected by putting a thin layer of plastic (a hydrogen source) over the rectangular slot. This will convert high-energy neutrons to protons, which can be detected because protons create ion pairs. Sensitivity is a few orders of magnitude less than sensitivity to alpha particles (as described above).
Email: EMF Meters
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