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Here are the questions most frequently posed to our service department, along with answers that, in some cases, must be generic.

Please feel free to address any of your concerns—from instrument problems and applications questions, to parts availability and pricing—to our service department.

What are considered "normal" breath readings?

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Normal breath readings will be between 80-150 ppb. Readings of the dental staff are often lower because of superior oral hygiene.

How about some greater detail on the significance of the numerical breath readings?

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Research reports about the etiologies of breath malodor agree that the vast majority of halitosis originates with the anaerobic bacterial degradation of sulfur containing amino acids within the oral cavity, resulting in the emission of hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and dimethyl sulfide (CH3SCH3), collectively referred to as volatile sulfur compounds (VSC).

The Halimeter® responds to all three volatile sulfur compounds, and gives a reading of total VSC’s.

Here are the electrochemical reactions in the sensor:

H2S arrow 2H+ + S0 + 2e

2CH3SH arrow CH3 – S – S – CH3 + 2H+ + 2e

CH3 – S – CH3 + 2H2O arrow 2CH3OH + S0 + 2H+ + 2e

To be rigorous, the Halimeter® does not respond equally to all three compounds, nor are all three compounds present in the same proportion in all patients—or even in the same patient—at all times. The relative amounts of these compounds are affected by diet, and the extent of anaerobic bacterial growth.

Elucidating the precise breakdown of the three compounds in an oral malodor sample requires a gas chromatograph, an instrument clearly beyond the scope of the typical dental office, and rare enough even in academic dental research settings. Fortunately, the additive reading provided by the Halimeter® correlates extremely well with organoleptic panels of trained human olfactory evaluators, and compares admirably with chromatographic testing.

At levels of 200-300 ppb, oral malodor is noticeable by an observer standing close to the patient.

At 350-400 ppb, the odor is noticeable by an observer standing several feet away from the patient.

At 500-700 ppb the odor is more noticeable not because it is “stronger,” but because it is more foul.

At over 1000 ppb, the odor will linger for several minutes after the patient leaves the room.

As in all biological parameters, Halimeter® readings should be used not so much as absolute standards, but as relative indicators of a condition. That is, a “normal” blood pressure reading is said to be 120/80. While 180/110 would be an indication that the patient should look into his condition, a reading of 130/82 would not.

My Halimeter® is displaying a normal reading or even a very low reading, even though the patient has noticeable halitosis.

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Remember that the Halimeter® responds to sulfur compounds. Although most oral malodor is sulfur-based, it is possible that the odor you smell is not being caused by sulfur compounds.

A very low reading, and/or sluggish instrument response, indicates that the sensor is nearly dead. It will then be necessary to replace the sensor.

Why am I getting inconsistent or erroneous readings?

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If the sensor is more than a couple years old, it is possible to experience erroneous readings. You might obtain a low reading and high reading on the same patient during the same session. This is due to the sensor decaying and thus being in need of replacement.

How long should the sensor in my Halimeter® last?

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Under normal use, the sensor will last 2-3 years. An indication that the sensor needs to be replaced is a slow and sluggish response to breath readings, or no readings at all.

How often should my Halimeter be calibrated?

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Our experience has shown that the sensor usually needs to be replaced before re-calibration is necessary. Contact our service department for current pricing on re-calibration and sensor replacement. If the sensor is more than a couple of years old, we suggest replacing it, as even if it is re-calibrated, there is no reliable way to estimate how much longer it will last.

What is the normal turnaround time for recalibration or repair?

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Normally, we can repair or recalibrate the instrument within one week of receiving it.

Do I need a return authorization for returning the Halimeter® or sensor for recalibration?

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Yes.   Please contact our service department for instructions.

Phone:1 800 458-6153 ext 121   (US and Canada)
(818) 882-2331 ext 121      elsewhere

Fax:(818) 341-0642

Our shipping address is:
Interscan Corporation
ATTN: Repairs
4590 Ish Drive #110
Simi Valley, CA  93063

My Halimeter® readings are jumping all over the place and the sensor is new; or I am witnessing the readings jumping ±100-200 ppb.

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All new sensors are a little more sensitive than the sensor you replaced. Remember that the instrument is reading in ppb (parts-per-billion) levels. As time goes by, a new sensor will calm down a bit. It is normal for the Halimeter®readings to jump ±10 ppb.

If you are observing the instrument spiking quickly either positive or negative, and returning to “000” quickly after the spike, it is possible that the Halimeter® is experiencing RFI (radio frequency interference). This could be caused by a cell phone, walkie-talkie, pager, etc. If your dental office is close to a radio station, or in a high rise building where large antennas are being used, the instrument is acting like a radio and is picking up the radio waves. It may be possible to mitigate these effects.

Why is the ball (float) in the flowmeter stuck at the bottom or top of the flowmeter?

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As the instrument gets older, there can be an accumulation of particles of dust or dirt, that have been drawn into the Halimeter®. These particles can prevent the ball from moving. If you tap the top of the flowmeter with an object, this should release the ball.

Why does the ball (float) in the flowmeter appear to move from the line that it is on, or bounce around?

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The flowmeter on the Halimeter® is not intended to precisely indicate the sample flow rate. Rather, it shows the user that sample is indeed flowing through the unit. For reasons discussed in the previous question, and owing to the somewhat pulsating flow of the instrument’s diaphragm pump, it is not uncommon for the ball to bounce a bit, or move from line to line.

What is the proper length of the straw to be used for breath sampling?

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The length is not the critical specification. The diameter and wall thickness are critical. The diameter specified below produces an optimal sealing surface (between the straw and coupling), while the thickness provides structural integrity to prevent crimping. The diameter and wall thickness work in conjunction to achieve an optimum seal, thus preventing dilution due to air leaks.

Testing in our lab recommends the use of the Dixie JW7. This is a 7.75 inch (196.85 mm) translucent polypropylene straw. Outside diameter is 0.217 in. (5.512 mm), with a wall thickness of 0.007 in. (0.1778 mm). No active chloride is present. There is no absorption of sulfur containing gases, such as would be expected in breath samples.

Packs of 1000 of these straws are available from us, if desired.

It should be noted that bending the straw sideways by more than 15 degrees could cause a break in the seal, thus diluting the sample.

How do I properly dispose of an old sensor?

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Dispose of an old sensor the same way you would dispose of an old car battery. Facilities exist in most communities to handle this type of waste.


If I need to replace the tubing at the inlet of the instrument, how long should the tubing be?

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The Halimeter® is shipped with 12 inches (305 mm) of tubing. You should never use more than 2 feet (610 mm) of tubing, as sample loss can occur. Remember, you are measuring ppb (parts-per-billion). Contact us for recommendations on the type of tubing to use.

Where can I obtain a copy of the Halimeter® instruction manual?

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You can download a copy of the manual directly from our website.

Where can I obtain a copy of the Halimeter® Recorder instruction manual?

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You can download a copy of the manual directly from our website.

Constant Improvement Policy

We intend to greatly expand this section, based on our experience, as well as your suggestions! Please send all relevant comments and suggestions to our service department.