GREISINGER 8921 Digital Sound Level Meter Owner’s Manual

: June 13, 2024
: GREISINGER

Table of Contents

GREISINGER 8921 Digital Sound Level Meter
INTRODUCTION
WARRANTY
FRONT PANEL DESCRIPTION
MEASURING SOUND LEVELS
SELECTING A AND C WEIGHTING
SELECTING THE RESPONSE TIME
USING THE BACKGROUND NOISE ABSORBER
SELECTING AUTOMATIC AND MANUAL RANGING
AUTOMATIC SHUTOFF
SPECIFICATIONS
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

GREISINGER 8921 Digital Sound Level Meter

INTRODUCTION

Your digital sound level meter provides automatic or manual ranging in six measurement ranges from 30 to 130dB. The unit meets ANSI S1 .4 and IEC 651 Type 2 standards and features 0.1dB resolution.
A background noise absorber permits you to measure sound levels accurately even in the presence of high background noise.
The meter allows you to select between fast and slow response times and A and C weighting. A maximum hold function is provided.
Jacks on the meter provide both AC and Dc analog output, while an RS-232 interface allows you to use an optional cable to capture sound level data on a PC.

WARRANTY

We warrant this product against defects in materials and workmanship for a period of one (1) year from the date of purchase and agree to repair or replace any defective unit without charge. This warranty does not cover probes, batteries, or damage resulting from accident, misuse, or abuse of the product

FRONT PANEL DESCRIPTION

MICROPHONE
LCD DISPLAY
ON/OFF – Power button
REC – Records sound level readings
MAXHLD – Freezes the maximum sound level digital reading
C/A – A/C frequency weighting selector
BA MODE – Background noise absorber
F/S – Fast/slow response selector
DOWN – Adjusts the measurement range
UPPER -Adjusts the measurement range
DC 9V – DC adapter jack
CAL – Calibration screw
AC OUT – AC analog output jack
DC OUT – DC analog output jack
RS232 – RS-232 output jack
BACKLIT-Back light (8922 only)

MEASURING SOUND LEVELS

Sound levels are displayed both digitally and in a bar graph. The digital display is updated every 160ms, while the bar graph is updated every 40ms.

Press the ON/OFF key to turn the meter on. The unit will first display the full screen and then count down to zero.

The meter will now begin measuring the current sound levels.
Point the microphone toward the source of the sound to be measured.

SELECTING A AND C WEIGHTING

When you turn the meter on, it will be in A weighting mode. A weighting enables the meter to respond in the same manner as the human ear, which increases and decreases amplitude over the frequency spectrum.
Applications for A weighting include OSHA regulatory testing, environmental measurement, workplace design, and law enforcement.
C weighting is suitable for flat response measurements with no increase or decrease of amplitude over the frequency spectrum.
Applications for C weighting include the sound level analysis of engines and machinery.
Press the C/A key to toggle between A and C weighting. A small A or C will be displayed on the right side of the screen to indicate the current mode.

SELECTING THE RESPONSE TIME

You can select fast or slow response times to suit different applications and standards. For example, most OSHA-related testing is done using slow response time and A-weighting.
When you turn the meter on, it will be in fast response mode. Press the F/S key to toggle between fast and slow response. A small FAST or SLOW will be displayed on the right side of the screen to indicate the current mode.

FREEZING THE MAXIMUM SOUND LEVEL READING

Press the ON/OFF key to turn the meter on.
When measuring sound levels, press the MAXHLD key to freeze the maximum reading. MAX HOLD will be displayed. The digital display will remain unchanged until a higher reading is detected. Note that the bar graph will continue to record the current reading.
Press the MAXHLD key again to exit maximum hold mode.

RECORDING THE MAXIMUM AND MINIMUM MEASUREMENTS

Press the ON/OFF key to turn the meter on.
Press the REC key. REC will be displayed on the bottom of the screen. The meter will begin tracking the maximum and minimum sound level measurements.
Press the REC key again. MIN will appear on the bottom of the screen and the minimum sound level measurement will be displayed. The unit is not recording at this time, but the bar graph will continue to show the current reading.
Press the REC key again. MAX will appear on the bottom of the screen and the maximum sound level measurement will be displayed. The unit is not recording at this time, but th bar graph will continue to show the current reading.
Press the REC key again to resume recording and repeat the process.
Press and hold the REC key until the REC indicator disapappears to exit recording mode.

USING THE BACKGROUND NOISE ABSORBER

This feature allows you to measure equipment noise accurately, even in the presence of high background noise.

Press the ON/OFF key to turn the meter on.
Press the MAXHLD key. MAX HOLD will be displayed.
Press the BA MODE key. F will be displayed to the left of the SPL(sound pressure level) icon. The digital display will show the background noise level.
Press the MAXHLD key again and MAX’ HOLD will be displayed. The meter is now ready to measure the actual machine noise.
Turn on the machine you want to measure and note the new sound level reading. This number represents the sound level of the device without the background noise. If there is no change in the reading, the background noise is greater than the noise of the device.
Press the MAXHLD key and then the BA MODE key to exit background noise absorber mode.

BACKLIT KEY (8922 only)
Offer a light for approximate 5 seconds to make it easier to see the display in the dark

SELECTING AUTOMATIC AND MANUAL RANGING

The meter features six measurement ranges in 10d8 steps: 30-B0dB, 40~90d8, 50~100dB,60~110dB, 70~120d8, 80~130d8.
When you turn the meter on, it will be in automatic range mode and a small AUTO will be displayed on the left side of the screen. In this mode, the meter will adjust the measurement range automatically for accuracy. The two digit number to the left of the bar graph on the LCD will show the low end of the current range.
You can also set the range manually. This is helpful when you know the measurement range in advance. The meter will be able to take readings more quickly, because the unit does not need to first establish the range before displaying the measurement.

To adjust the range manually:

When measuring sound levels, press the DOWN and UPPER keys as needed to adjust the measurement range. MANU will appear on the display. Note that the two digit number to the left of the bar graph will change to reflect the low of the newly selected range.
Press and hold the DOWN or UPPER key to switch back to automatic ranging. If the meter is operating in manual range and UNDR is displayed, the sound is too low or the range. If UPER is displayed, the sound is too loud. In either case, you must adjust the measurement range or your readings will be inaccurate

AUTOMATIC SHUTOFF

The meter will turn off automatically after 20 minutes to preserve the battery.

To override this feature:

Make sure the unit is turned off.
Press the ON/OFF and MAXHLD buttons simultaneously.
When the full display appears, release the MAXHLD button first.
Release the ON/OFF key. The meter will remain on until the ON/OFF button is pressed again.
The automatic shutoff feature will resume the next time the meter is turned on.

REPLACING THE BATTERY

When the entire display flashes, the 9V battery has fallen to a critically low voltage level and should be replaced as soon as possible. Use a screwdriver to unscrew the back battery compartment cover. Insert a fresh 9V battery and replace the cover.