1200/2200
Sound Level Meters
Operator's Manual
Note: Due to the new ATEX Directive in Europe, all references in this
document to "Ex" or "EEx" for intrinsic safety approvals should be disregarded
effective 7/1/03 within the member countries of the European Union (EU). At
this time, this product is not approved in accordance with the new ATEX
Directive and is not sold for use in hazardous atmospheres or explosive zones by
customers within the EU. Outside of the EU, all references to intrinsic safety
continue without change.
Thank you for choosing Quest Technologies to meet your sound measuring
needs. The Quest 1200 Sound Level Meter is a light weight easy-to-use Type 1
instrument and the 2200 is our Type 2 model. It is our goal to make your decision to buy Quest products the right one, and to provide support for an y questions or concerns that might arise.
The purpose of this manual is to provide the user with the n ecessary information
to operate the 1200/2200 Sound Level Meter as well as the remoteable versions
of the 1200R/2200R. The entire manual should be read to fully understand the
many features this instrument offers.
This manual is not all inclusive and cannot cover al l unique situations. In addition, no warranties are contained in this manual except as described under the
warranty policy section.
Copyright 2000
Revision A
P/N 056-653
1060 Corporate Center Drive • Oconomowoc, WI 53066 USA • 800-245-0779 • Fax: 262-567-4047
http://quest-technologies.com Printed in U.S.A
1. INTRODUCTION..................................................................................1
2. GENERAL OVERVIEW......................................................................2
2.1 The Display....................................................................................2
2.2 Meter Controls...............................................................................3
2.2.1 OFF/PAUSE/RUN Switch..................................................3
2.2.2 SPL/LEQ/RT/MAX/MIN/% OL Switch.............................3
2.2.3 FAST/SLOW/PEAK/IMP RESPONSE Switch .................4
2.2.4 A/C/Z Switch ......................................................................4
2.2.5 RANGE (dB) Switch...........................................................4
2.2.6 RESET Button.....................................................................5
2.2.7 CAL Button.......................................... ...............................5
2.3 Output Jack ....................................................................................5
2.3.1 DC Output Function ...........................................................6
2.3.2 AC Output Function ...........................................................6
3. METER INTEGRITY .......................................................................7
3.1 Power On/Battery Check...............................................................7
3.1.1 Battery Replacement............................................................7
3.2 Setup…………..............................................................................7
3.2.1 Changing the Exchange Rate ..............................................7
3.2.2 Changing the Calibration Level ..........................................7
3.3 Calibration.....................................................................................8
3.3.1 Calibration Check ................................................................ 8
3.4 Switch Settings to Select Measurements .......................................9
4. OPERATION......................................................................................10
4.1 Meter/Microphone Placement ..................................................10
4.2 Background Noise.....................................................................10
4.3 Windscreen Effects ...................................................................11
4.4 Data Recording/DATALOGGING............................................12
5. TECHNICAL INFORMATION.....................................................13
5.1 Principles of Operation...............................................................13
5.2 Microphone ...............................................................................13
5.3 Weighting Characteristics .........................................................15
5.4 Tone Burst Response.................................................................15
6. SPECIFICATIONS..........................................................................18
7. ACCESSORIES................................................................................21
QUEST SERVICE POLICY......................................................................22
QUEST WARRANTY POLICY................................................................23
1. INTRODUCTION
The Quest models 1200 and 2200 and their remote versions
(1200R/2200R) are Impulse and Integrating Sound Level Meters for
measuring frequency weighted and time averaged SPL, weighted or
unweighted Peaks or frequency weighted Leq. Applications include
laboratory, industrial, community and military, measurement or analysis.
The models 1200 and 2200 are easy-to-use hand held meters with an LCD
display that provides a numerical readout. They are housed in an R.F.
shielded injection molded case. The meter is operated with simple slide
switches. An output jack on the bottom of the meter is provided for connecting to peripheral devices such as chart recorders, oscilloscopes, audio
recorders, etc.
The model 1200 provides Type 1 accuracy for precision measurements
while the model 2200 provides Type 2 accuracy for general field survey
work. As both meters are operationally identical, this manual will refer
only to the model 1200 except where appropriate.
2. GENERAL OVERVIEW
2.1 The Display:
The LCD display provides a numeric readout in 0.1 dB increments along
with a LOBAT (low battery) indicator. The LOBAT indicator will turn on
when the voltage of the battery is too low to allow an accurate reading.
A plus sign '+' will appear on the left side of the display if signal peaks
cause an overload condition in the electronics. If the signal falls below the
measuring range, 'UR' (under range) will be displayed.
2.2 Meter Controls:
2.2.1 OFF/PAUSE/RUN Switch:
• OFF - In this position the power is removed from the instrument.
• PAUSE - In SPL mode the meter continuously displays sound pressure
level according to the RESPONSE and WEIGHTING settings. In other
modes the meter will display the appropriate value for the previous RUN or
'---' if no run time has been accumulated. The meter automatically updates
the current reading at a rate of once per second.
• RUN - Causes the meter to begin calculating the frequency weighted
equivalent continuous SPL. All SPL measurements are integrated into a
single number repres enting the equivalent SPL for the entire measurement
period. This measurement will continue until the meter is placed in the
PAUSE mode or reset. Maximum RUN time is 100 hours or as long as the
battery lasts.
2.2.2 SPL/LEQ/RT/MAX/MIN/%OL Response Switch:
This six position switch determines the display mode of the meter.
• SPL - In the SPL mode the numeric display provides a reading of the
maximum sound pressure level measured during the previous second.
• LEQ - In the LEQ mode, the display indicates the integrated , or average
level for the RUN period. If no RUN time has been accumulated the display
shows dashes.
• RT - In the RT mode the display shows the elapsed time of the current o r
last RUN. The RT mode consists of two or three displays. The first is RUN
TIME seconds ':XX'. The second is RUN TIME hours/minutes 'XX:XX'.
Pressing the CAL button while in the RT mode toggles the meter between
these two displays. If the RUN TIME exceeds 20 hours, there will be a third
display that will show hours up to 99 'h:XX'. If no RUN time has been
accumulated the display shows dashes.
• MAX - In the MAX mode the display holds the highest reading
encountered during the RUN period. If no RUN time has been accumulated
the display shows dashes.
• MIN - In the MIN mode the display holds the lowest reading encounte re d
during the RUN period. If no RUN time has been accumulated the display
shows dashes.
• %OL - In the %OL mode the display shows the time that the circuitry has
been overloaded as a percent of RUN TIME. If no RUN time has been
accumulated the display shows dashes.
2.2.3 FAST/SLOW/PEAK/IMP Response Switch:
The Response Switch controls the rate at which the meter responds to
changing input signals. Most sound measurements are done with the
response set to SLOW (S). The FAST (F) response is generally used when
measuring short duration noises such as moving vehicles. PEAK (P) is
useful when measuring the absolute peak of the sound pressure wave.
IMPULSE (I) is used for impulsive or transient sounds.
The Response switch positions are as follows:
• FAST (F) - 125 millisecond time constant. (See Figure 10) Decay Rate =
34.7 dB per second.
• SLOW (S) - 1 second time constant. (See Figure 11) Decay Rate = 4.35
dB per second.
• PEAK (P) - 50 microsecond time constant.
• IMPULSE (I) - 35 millisecond rise time constant, 1.5 second decay time
constant. (See Figure 12)
2.2.4 A/C/Z Switch:
The A/C/Z switch controls the frequency response (weighting) of all
measurements. (See Figure 9)
2.2.5 RANGE (dB) Switch:
The displayed range of the model 1200 is 70 dB and is switchable between
(30-100dB),(50-120dB), and (70-140 dB). After switching ranges allow
several seconds for the met er electronics to stabilize. If a ra nge change is
necessary during a LEQ study, it is good practice to firs t set the meter to
LEQ PAUSE, change range and then set the meter to RUN. This will avoid
integrating any handling or switching noise into the LEQ measur em ent.
2.2.6 RESET Button:
This button is used primarily to cl ear data from the memory of the
instrument. When pressed, the display will begin to count down from '02'. If
the button is pressed and held, the display will coun t down '02,01, ---'. When
the dashes are displayed t he instrument memory is clear.
This button is also used as an up-arrow during setup, (see Operating
Procedure)
2.2.7 CAL Button:
This button has three functions; It initiates a calibration, toggles between Run
Time displays, and acts as a down arrow during setup, (see Operating
Procedure)
2.3 Output Jack:
The model 1200 provides an output jack on the bottom of the meter for
measuring the weighted AC signal before the rms/log detector and the DC
output of that detector. Both signals are real time, i.e. LEQ is not
represented at the DC output. This jack may be connected to any load
without affecting the operation of the meter. Connection to low impedance
loads will require correction for the 1 Kohm impedance of these outputs and
will also decrease battery life.
The output jack takes a 3.5mm stereo plug. (See Figure 2, Output Jack
Connections.)
2.3.1 DC Output Function:
The SPL or PEAK level over the range selected is linearly re presented by a
DC output. The output changes 16.7mV/dB or 1V/60dB. This output is
provided for connecting a 0 to 1 volt span data recorder. (See section 4.4
Data Recording)
2.3.2 AC Output Function:
This jack provides the amplified, frequency weighted AC signal at the input
of the RMS detector.
3. METER INTEGRITY
3.1 Power On and Battery Check:
Set the OFF/PAUSE/RUN switch to either the PAUSE or RUN position as
desired. At any time, other than initial turn-on, if the LOBAT indicator is
displayed, the user must replace the battery. A 9 Volt Alkaline battery is
recommended for best performance.
3.1.1 Battery Replacement:
Slide the battery door t o t he left to open the battery compartment. Refer t o
the sticker inside the compartment fo r proper battery orientation.
3.1.2 Rechargeable Batteries:
Nicad type rechargeable (9V batteries (such as Radio Shack® 23-299 7.2 V,
120 mAh) and an appropriate charger may be used with the 1200. The fact
that nicad 9 V replacement cells typically operate at 7.2 V will be observed
as shorter battery life (approximately 8 hours with Radio Shack® 23-299).
At the appearance of the LOB AT indicator the nicad battery must be
recharged.
NiMH (Nickel-Metal-Hydride) batteries are NOT recommended. This is
due to the excessive discharge of the typical NiMH cell prior to the voltage
dropping low enough to activate the LOBAT indicator.
3.2 Setup:
NOTE: There may be times when it is necessary to change the Exchange
Rate or Calibration Level that is stored in the meter. Both of these items are
accessible during the power-up sequence.
The power-up sequence is as follows:
1. All display segments turned on for 2 seconds.
2. The meter firmware revision 'rX.X' for 2 seconds.
3. The current Exchange Rate or Doubling Rate 'Er3' or 'Er5' for 3
seconds.
4. The current Calibration Level for 3 seconds.
3.2.1 Changing the Exchange Rate:
Turn on the meter.
When 'Er3' or 'Er5' appears in the display, press both the CAL and RESET
button simultaneously until dashes are displayed.
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