Radio Shack 33-2055A Manuel d'utilisateur télécharger pdf

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Setting the Meter

Setting the Weighting

Press WEIGHTING to select A or C.

Weighting determines the meter’s frequency response

curve.

A-weighting has A-curve frequency characteristics and

causes the meter to respond mainly to frequencies

ranging from 500 to 10,000 Hz. This is the human ear’s

most sensitive range. Select A to determine the noise

level of an area.

C-weighting has C-curve (ﬂat) frequency characteristics

and causes the meter to respond mainly to frequencies

ranging from 32 to 10,000 Hz. Select C to measure

sound levels of musical material.

n Note: You can change the weighting setting only during

a continuous average or maximum measurement.

Setting the Response Time

Press RESPONSE to select FAST or SLOW.

When set to FAST, the meter updates the bar graph

every 0.2 seconds. When set to SLOW, the meter

updates the bar graph every 0.5 seconds.

n Note: You can change the response setting only during

a continuous average or maximum measurement.

Understanding Indications

Level Indicator

The meter displays sound level using a number and a

bar graph. The number shows the sound level in dB

within ±10 dB of the selected range and is updated

once a second.

The bar graph’s center point represents the midpoint

of the selected range (for example, for Range 70, the

center point represents 70 dB). The bar graph updates

every 0.2 seconds or 0.5 seconds.

Overrange Indicator

When the sound level is higher than the highest

number in the selected range, the bar graph goes to

+ 10 dB and both the bar graph and the number that

represents the next range ﬂash.

For example, if the meter measures 91 dB in Range

80, then the number 90 and the bar graph ﬂash. If the

meter measures more than 126 dB in Range 120, the

number 126 and the bar graph ﬂash.

If you get the overrange indicator, try a higher range

setting until you get a reading in the upper half of the

range (0 to +10 dB).

Underrange Indicator

When the measured sound level is lower than the

lowest sound level of the selected range, LO appears

and the bar graph disappears. If this happens, try the

next lower range.

n Notes:

• The overrange or underrange indicator can also appear

when you recall a reading using the measurement

holding function and the measurement is under or over

the selected range.

•

The meter can measure sound levels only from 50 to 126 dB.

Taking Measurements

Continuous Average Measurements

Follow these steps to measure the average sound

level.

1. Set RANGE to the desired range setting. If the

sound level is very high, start at the highest range

setting (120) and reduce the setting until you get a

reading.

There are seven ranges. Each covers 20 dB. The

number of a range represents the center of the

range. When the measured value is lower or higher

than the set range, an underrange or overrange

indicator appears. See “Underrange Indicator”

and “Overrange Indicator” on this page. Take

measurements at several different points in the area

to get a good average.

n Notes:

• If you set RANGE to 120, the meter measures sound

levels from 110 to 126 dB.

• If you change the range setting during a

measurement, you clear all the current data and a

continuous average measurement resumes.

2. Set the weighting and response (see “Setting the

Weighting” and “Setting the Response Time” on this

page).

3. Point the meter’s microphone at the sound source.

The meter displays the continuous average sound

level during a one-second sampling period and

updates the number on the display once a second.

4. After the measurement, set RANGE to OFF.

Taking Maximum Measurements

Follow Steps 1-3 in “Continuous Average Measurements”.

2. Press MAX; the word MAX appears.

The meter displays only the loudest measured

sound level during the one-second sampling

period. The bar graph shows the maximum level of

every 0.2 or 0.5 seconds.

The bar graph segment that corresponds to the

peak reading stays on the display for 2 seconds or

until the meter measures a higher maximum level.

3. Press MAX again to cancel the continuous

maximum measurement. A continuous average

measurement resumes.

Integrated Average Measurements

Follow these steps to monitor the sound level and

average the measurement over a period of 1 to 199

seconds. The meter stores the average, maximum, and

minimum sound levels during the set time.

1. Press and hold DH for about 2 seconds during a

continuous average or maximum measurement.

The digit 1 appears.

2. Press (or press and hold) MAX or MIN to set a

period from 1 to 199 seconds; position the meter

for the measurement.

3. Press RESET to start the monitoring.

The meter updates the current integrated average

display once a second. MIN and MAX ﬂash until the

set time is up. When the set time is up, DH appears,

and MIN and MAX go on ﬂashing. The meter displays

the total integrated average sound level.

4. Press MAX to display the maximum sound level

for the set time, press again to return to the total

integrated average sound level.

Press MIN to display the minimum sound level

for the set time, press again to return to the total

integrated average sound level.

5. Press RESET after you check the average, maximum,

and minimum sound levels. A continuous average or

maximum measurement resumes.

n Notes:

• If you change the RANGE setting during an integrated

average measurement, you clear any stored data and a

continuous average or maximum measurement resumes.

• You must repeat the procedure for taking an integrated

average measurement.

Taking Maximum and Minimum Measurements

during an Undetermined Time Period

1. Press RESET during a continuous average or

maximum measurement. At the end of the desired

time period, press DH. DH displays.

2. Press MAX and MIN respectively to check the

average, maximum (MAX stops ﬂashing), and

minimum (MIN stops ﬂashing) sound levels during

the time period.

3. Press RESET to resume a continuous average or

maximum measurement.

Checking Stereo System Acoustics

To check the sound of a stereo system, use an audio

sample that produces pure tones, one at a time, at

intervals that span the entire audio spectrum. Use

C-weighting with either slow or fast response.

Make a graph or table to show the sound level

each tone produces. This gives you a clear idea of

the frequency response of the total audio system,

including the room. To smooth out the response,

adjust the tone control, change speaker placements,

and use a frequency equalizer.

Holding Measurements

You can store the current measurements in memory

and freeze measurements on the display. The meter

stores the average, maximum, and minimum sound

levels for the last one second.

1. Press DH during a continuous average or maximum

measurement. DH displays and the last average or

maximum measurement is frozen.

2. For an average measurement, what is frozen is the

last average reading. Press MAX to check the last

maximum measurement. MAX displays. Press MAX

again to return to the average measurement.

For a maximum measurement, what is frozen is the

last maximum reading.

3. Press MIN to check the last minimum measurement.

MIN displays. Press MIN again to return to the

average or maximum measurement.

4. Press RESET to return to the continuous average or

maximum measurement.

n Note: When you set RANGE to a different range during

measurement holding, you disable the holding function and

return to a continuous measurement.

33-2055 RC_En.111208.indd 1 12/05/2008 9:59:47

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Résumé du contenu

Page 1 - Taking Measurements

Page 2 Page 3Setting the MeterSetting the WeightingPress WEIGHTING to select A or C.Weighting determines the meter’s frequency response curve.A-weight

Page 2 - Limited Warranty

User’s Guide 33-2055Digital Sound Level MeterThank you for purchasing your Digital Sound Level Meter from RadioShack. Please read this user’s guid

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Radio Shack 33-2055A Manuel d'utilisateur

Naviguer en ligne ou télécharger Manuel d'utilisateur pour Multimètres Radio Shack 33-2055A. displays - Aktinion [en] Manuel d'utilisatio

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