Geneq > Environnement > Gaz - Détecteurs

Mesureur portatif de formaldéhyde
modèle Z-300

FEATURES

  • Meets OSHA Accuracy Requirements
  • Time Weighted Average (Variable Intervals)
  • Battery Status LED
  • Data Logging Available
    (Model: ZDL-300)

Introduction

Environmental Sensor Co.’s Formaldehyde Meter is a hand held instrument that measures formaldehyde concentration in a range of 0-30 ppm and a resolution of 0.01 ppm. The instrumentmakes it possible tomonitor Formaldehyde vapor in air, while performing operations using Formaldehyde solution.

The instrument has an LCD display giving concentrations in ppm, a low battery indicator, and an audible alarm that can be set at any level from 0-30ppm. With the optional data logging feature, themeter stores all of the exposure points for up to 5 logs (a log is created in the instrument’s internal memory each time it is used). A log contains: date, time, number of exposure points, the interval between each point, and the actual exposure points. All of the log files easily uploaded to PC using components available within theMicrosoftWindowsOperating System or the terminal software included with the instrument.

Eliminates interferences

The Z-300 Formaldehyde uses two filters to eliminate many of the common interferences. Measurements are first made with a filter that permits determination of the background or baseline. Insertion of a second filter then permits the measurement of formaldehyde. The instrument prompts the user for all required actions.

The procedure is simple. Insert one filter, remove it, and insert another. With the use of the filter system, interferences are virtually completely removed. Only certain aldehydes and ketones need to be considered. The filters do not permit separations of these classes of compounds.

Performance data
Nominal Range 0-30 ppm
Maximum 34 ppm
Resolution 0.01 ppm
Zero Drift <0.002 PPM/min.
Response Time
90%Peak		 <60 seconds
Warm-Up Time 3 min. normal conditions
Repeatability 1% of signal
Zero Drift <0.002 ppm
per minute
Sensitivity Loss <5%per year
Operating Temperature 0-40°C
Pressure Range Atm±10%
Relative Humidity
Range (non-condensing)		 15-90%
Alarm Audible, 80db
Dimensions HxDxW
4.75”x2.5”x1.5”
Weight 170 gms
Power Source 9 Volt Battery

Theory of operation

The sensing element of the instrument is an electrochemical cell. The cell is a four-electrode type, which contains a working and an active auxiliary electrode. The signal from the auxiliary electrode is used for temperature compensation and to improve the selectivity of the entire sensor. The sensor response is linear with the concentration of Formaldehyde in air.

Interferences

Some representative examples of the common compounds and the corresponding signals they give are shown below. Care needs to be exercised about using this instrument in the presence of large concentrations of interfering gases. Contact the manufacturer if difficulties are suspected with other gases, or with other usage problems.

In addition variations of the baseline, resulting from varying concentrations of compounds other than aldehydes or ketones, during the course of the measurement (about three minutes), can impact the reading.

Z-300 Formaldehyde Meter / Cross-Sensitivity Data

Gas
Sensor Interferences
% of Formaldehyde
Interferences After
Use of Filters
Acetone
2
2
Methylethyl Ketone
2
0
Diethyl Ketone
2
2
Acetaldehyde
12
0
Acetic Acid
0
0
Ethylene
67
0
Methanol
125
0
Ethanol
55
0
I-propanol
44
0
Carbon Monoxide
40
0

Safety

The instrument is designed to be intrinsically safe when the recommended low discharge rate 9-volt battery is used. There is insufficient energy to ignite a combustible gas mixture.

Data Logging (Optional)

The meter stores all of the exposure points for up to 5 logs (a log is created in the instrument’s internal memory, for each use). Each log contains: the date, the initial time, the number of exposure points, the interval between each point, and the all of the individual exposure points. One log can store up to 2,880 samples at 10sec interval. The data is easily uploaded to PC using components available within the Microsoft Windows Operating System or the terminal software included with the instrument.