Quest Technologies M-27

To Next Page

TABLE OF CONTENTS

INTRODUCTION……………………………………………………………………………………….3

M-27 SIMPLIFIED OPERATING INSTRUCTIONS…………………………….…………………..5

Control Keys…………………………………………………………………………..……..5

Sound Level Meter Keys……………………………………………….…………………..6

Dosimeter Keys………………………………………………………………………….…..6

Time Keys……………………………………………………………………………………..7

Event Keys……………………………………………………………………………………7

Procedure to Accumulate Event Data…………………………..……………………….7

Setting the Clock……………………………………………………………..……………..8

Recording the Calibration Level………………………………………………….………8

Using a Printer……………………………………………………………………………….9

Dumping Raw Data……………………………………………..…………….……………11

Changing Printer Parameters……………………………………….……….…………..11

SPECIFICATIONS………………………………………………………………………….…………11

GENERAL DESCRIPTION…………………………………………………………………………..12

PRINCIPLES OF OPERATION……………………………….……………………….…………….13

General……………………………………………………………….………………………13

Weighting Characteristics………………………………………………….……………..13

Microcomputer Modes…………………………………..…………………………………14

Formulas and Definitions……………………………………….…………………………16

TESTING AND CALIBRATION………………………………………………………………………17

Battery Test…………………………………………………………………………………..17

Battery Replacement……………………………………….……………………………….17

Microphone Replacement……………………………………………..…………………..18

Calibration and Maintenance…………………………………………………..………….18

Daily Calibration……………………………………………………………………………..18

Altitude Corrections……………………………………..………………………………….19

OPERATING PROCEDURE…………………………………………………….………………….…19

As a Personal Noise Dosimeter……………………..……………………………………19

As an Area Monitor………………………………………………..………………………..20

As a Survey or Event Monitor…………………………………………….………………21

Effects of Operator's Presence……..……………………………………………………22

Use with Windscreen……………………………………………………………………….22

Using a Printer……………………………………………………………………………….23

Connections to Printer……………………………………………………………………..24

Sample Printouts………………………………………………………..…………………..24

Memory Map……………………………………………………………………………..…...30

Editing Printout………………………………………………………………………………31

Printer Setup……………………………….…………………………………………………32

EXTENDING BATTERY LIFE………………………………………..……………………………….33

INTERNAL SWITCHES………………………………………………………………..….…………..34

Switch Positions……………………………………………………………………….……36

Setting Internal Switches………………….………………………………………………38

Code Decoding…………………………………………..……………..…………………..41

TROUBLESHOOTING………………………………………………………….…………………….42

INTERPRETING RESULTS………………………………………………………………….………43

Use of Lavg and TWA……………………………………………………………………..43

Estimating TWA from Lavg…………………………..………………………………….44

Accuracy of Readings………………………………………..…………………………..44

Hints and Good Practices………………………………………….…………………….44

Considerations of Measurement and Accuracy…………………..…………………46

ACCESSORIES………………………………………………………………………………..……..47

QUEST SERVICE AND WARRANTY POLICY……………………………………………………48

Main Page

Need help?

Do you have a question about the Quest Technologies M-27 and is the answer not in the manual?

The Quest M-27 Noise Logging Dosimeter is a microcomputer-based sound analyzing instrument designed for accumulating, displaying, and sending data to serial or parallel printers or computers. It can function as a personal noise dosimeter, an area monitor, or a survey events monitor.

Function Description:

The M-27 accumulates noise data for OSHA hearing conservation, OSHA engineering controls, and equal energy noise dosimetry. It measures peak and maximum levels, 1-minute histograms, and 1 dB statistical distributions. The device is housed in a secure, dust-proof case and can be clipped onto a belt or shirt pocket for personal use, or tripod-mounted for area monitoring.

As an Events Monitor, it accumulates data for up to 16 separate events, including 3 integrated sound levels, 3 noise doses, 2 time-weighted averages (TWAs), a sound exposure level, peak level, maximum level, start time, and run time.

As an overall unit, the M-27 collects data for:

3 separate dosimeters
3 separate 1-minute time histograms
2 separate percent time statistical distributions
2 separate percent dose distributions
16 separate events
Sound levels, peaks, and maximum levels
Run time, pause time, and elapsed or real time

The unit displays:

Sound level, peak level, maximum level
2 integrated average levels, an equivalent sound level
3 percent doses
2 time-weighted averages, a sound exposure level, 16 separate events
Run time, pause time, and upper limit time (time greater than preset level)
Elapsed or real-time clock (12 or 24 hour)
Calibration level
Code of 24 internal switch settings

The unit prints out:

A heading
Summary of accumulated data and setup parameters
Up to 16 separate events
3 separate 1-, 3-, 5-, or 10-minute time histograms
2 percent time statistical distributions
2 percent dose statistical distributions
Raw data for computer storage and manipulations
Includes editing capability to print out only required data

Important Technical Specifications:

Standards: ANSI S1.4-1983 type 2, ANSI S1.25-1978, IEC 651 type 2
UL Intrinsic Safety: Class I Group C, D; Class II Group E, F; Class III
Detector: True RMS; 63 dB pulse range
Display: Liquid crystal display, Range: 01 to 2999
Annunciators: HTL, LTL, 3 dB, LOBAT, RUN, and PAUSE
Microphone: 8 mm PZT ceramic, 36-inch cable, field replaceable
Battery: Single 9-volt alkaline, 80-hour battery life
Battery Indicator: 8-hour battery life, 1 week data retention
Calibrator: External calibrator
Temperature: -15° to 50°C operating; -40° to 60°C storage (battery removed)
Humidity: 0 to 95% non-condensing
Magnetic Field Effects: Negligible below 50 Oersteds at 50 to 60 Hz
Size: 5½ x 2¾ x 1⅜ inches (140 x 70 x 40 mm)
Weight: 14 ounces (400 grams)
Construction: Cast aluminum housing with tamper-, water-, and dust-resistant security cover.
Frequency Weighting: "A" or "C" frequency weighting. "A" weighting is similar to human ear response, used for OSHA and most noise measurement requirements. "C" weighting is used for measuring noise reduction in hearing protectors and scientific purposes.
Time Constant: Fast or slow time constant. Present OSHA requirements specify Slow.
Upper Limits: 90, 115, or 140 dB.
Clock: 12 or 24 hour clocks.
Unit Numbers: 8 different unit numbers.
Printouts: Text, graph, or both printouts.
Printers: Serial or parallel printers.
Baud Rates: 300, 600, 1200, or 2400.
Line Feed/Carriage Return: Selectable.
Microcomputer: MC146805 CMOS Microcomputer with 8192 bytes of RAM, 6144 bytes of ROM, a 33-segment LCD, 24 programming switches, serial and parallel printer outputs, and a V/F converter for continuous dose integration.

Usage Features:

Control Keys:
- RUN: Starts or continues data accumulation, displays run time, used to start Events.
- PAUSE/RESET: Stops data accumulation, counts down from P-5 to P-1 (if held for 5 seconds, unit resets and old data is lost). Also used to reset Clock, Calibrator, Events, and pause Printout.
- ON/OFF: Turns unit on/off. If held down while ON, display counts down from 0-5 to 0-1 and then blanks, retaining data. Also turns off Print and Events.
- CODE/HL3: Cycles through 7 steps to display and print data in 7 ways, and displays internal switch settings code.
Event Mode: Enter by pressing EVENT, accumulate data with RUN, stop with PAUSE/RESET. Cycle to next event with RUN and PAUSE/RESET again. Exit with ON/OFF.
Printer Use: The M-27 can print to Centronics compatible parallel or serial printers. Printouts can be changed and edited before or during printing to output only desired data. Data is not lost during printing.
Data Dumping: Raw data can be transferred to a computer or printer for reprocessing, useful with additional computer programs.
Microphone Placement: For personal monitoring, the microphone should be on the shirt collar, high on the shoulder, away from the neck. For area monitoring, it can be tripod-mounted and aimed at a 70-degree angle to the noise source.
Windscreen: The WS-5 Windscreen is recommended to prevent wind from causing erroneous measurements.

Maintenance Features:

Battery Test: Press any key. "LOBAT" indicates low battery (8 hours life remaining).
Battery Replacement: Loosen 2 screws on back, remove back and battery. Replace with new 9-volt alkaline battery, observing polarity. Disconnecting the battery automatically erases stored data; use BX-9 Battery Change Adapter to preserve data during battery change.
Microphone Replacement: Field replaceable. Unscrew the knurled nut, replace with new microphone, and recalibrate unit.
Calibration and Maintenance: The M-27 maintains accurate calibration for months, but annual return for complete checkout and calibration is recommended. Daily calibration is advised before use, using a Quest calibrator with the 8 mm microphone adaptor.
Altitude Corrections: Calibrator sound levels are affected by pressure; correction is -0.1 dB for each 2000 feet above sea level.
Extending Battery Life: Remove the battery if the unit will not be used for a few days, as data is stored even when off.