TM INTERNATIONAL ® S.E. International, Inc. P.O. Box 39, 436 Farm Rd. Summertown, TN 38483 USA 1.800.293.5759 | 931.964.3561 | Fax: 1.931.964.3564 www.seintl.com | radiationinfo@seintl.
Contents Chapter 1: Introduction How The Inspector EXP Detects Radiation Precautions 3 3 3 Chapter 2: Features The LCD Display Indicators The Switches Mode Switch Off/On/Audio Switch The Backlight Set Button + and - Buttons The Detector The Input/Output Ports 4 4 4 5 5 5 5 6 6 6 6 Chapter 3: Operation Starting the Inspector EXP Units of Measurement Display Update Maximum level Response Time (Autoaveraging) Autoranging Operating in Dose/Rate Modes Operating in Timer Mode Taking a Timed Count Using Dose/R
Chapter 1: Introduction The Inspector EXP is a health and safety instrument that is optimized to detect low levels of radiation. It measures alpha, beta, gamma, and x-ray radiation (ionizing radiation only).
Chapter 2: Features The Inspector EXP measures alpha, beta, gamma, and x-ray radiation. It is optimized to detect small changes in radiation levels and to have high sensitivity to many common radionuclides. For more information, see Appendix A, Sensitivity to Common Radionuclides. This chapter briefly describes the Inspector EXP’s functions. For more information on how to use the Inspector EXP, see Chapter 3: Operation.
The Switches The Inspector EXP has 2 switches on the front and 3 buttons on the end panel. Each switch has 3 settings which are described below. Mode Switch Figure 2(2) mR/hr µSv/hr: The numeric display shows the current radiation level in milliroentgens per hour or, when SI units are used, in microsieverts per hour. • In mR/hr mode, The Inspector EXP displays the radiation level from .001 to 100. • In µSv/hr mode, The Inspector EXP displays the radiation level from .01 to 1000.
Set Button Figure 3 (5) The Set button is used to set the Alert or Timer in normal operating mode and to select items in the Utility Menu. See Chapter 3 Using the Alert, Taking a Timed Count, and Utility Menu. + and - Buttons Figure 3 (6) The + and - buttons are used to adjust the numeric display for timed counts, alert settings, and to make selections in the utility menu. Figure 3 The Detector CAUTION: The mica surface of the Geiger tube is fragile and should be handled with care.
Chapter 3: Operation Starting the Inspector EXP Before starting the Inspector EXP, ensure that the external probe is connected both to the unit and the probe end. Install a standard 9-volt alkaline battery in the battery compartment located in the lower rear (Figure 4). Note: Place the battery against the bottom wall, and make sure the wires are placed along the side of the battery and not under it.
Autoranging When radiation levels increase in some modes over certain preset levels, the Inspector EXP uses autoranging, automatically changing to the X1000 scale. While in CPM or Timed Count (Total/Timer) mode, whenever X1000 is shown above the numeric display, multiply the displayed reading by 1000 to determine the radiation level. mR/hr, µSv/hr, and CPS are not applicable. Mode Ranges as they are displayed CPM 0 to 2,999 CPM > 9,999 X1000 10.
To take a timed count, follow these steps: 1. With the Inspector EXP operating, set the Mode switch to Timed Count (Total/Timer). The display shows 0 and Total in the upper left portion of the display. 2. Press the SET button on the end panel to set the time for your count. You will see the hourglass, and the most recent timing period used. The first time you use the timer, the setting is 00:10 (ten minutes). 3. Use the + and - buttons to set the timing period.
Utility Menu The Utility Menu allows the user to change default settings for several operating parameters. Once a setting is changed, it remains in effect unless they are changed through the Utility Menu or the Observer USB Software. 1. To activate the Utility Menu, hold down the + button on the end panel while turning the instrument on. The display will show the MENU icon. Release the + button and donE will appear along with the MENU icon. The utility menu can be accessed even if the probe is disconnected.
Setting the Internal Clock It is necessary to set the internal clock to properly time stamp the data collection on your device. We recommend the clock be set prior to collecting data to ensure a correct time and date in your collected data. To set the internal clock, enter into the utility menu, select CLOC, and press set. 1. The seconds are displayed. Use the + and - buttons to select the seconds for the clock and press SET to select your choice. 2. The time will be displayed.
Checking for Surface Contamination To check a surface, hold the detector window close to the surface, and read the count rate (wait 30 seconds or until the reading has stabilized). If you want to find out if a surface is slightly radioactive, take a timed count or a longer accumulated count. Chapter 5: Maintenance The Inspector EXP requires regular calibration and careful handling to assure good measurements. Use the following guidelines to maintain the instrument properly.
Chapter 6: Basics of Radiation and Its Measurement Ionizing Radiation Ionizing radiation changes the structure of individual atoms by ionizing them. The ions produced in turn ionize more atoms. Substances that produce ionizing radiation are called radioactive. Radioactivity is a natural phenomenon. Nuclear reactions take place continuously on the sun and all other stars. The emitted radiation travels through space and a small fraction reaches the Earth.
Chapter 7: Observer USB Software The Observer USB reads in Total Counts, CPM, CPS, µR/hr, mR/hr, µSv/hr and has the ability to collect, log the data received, calibrate the unit, and echo the readings collected on a PC. The data is displayed on a graph as well as a digital on-screen meter and can be saved or printed in various ways, including a spreadsheet format. The dwell/count time can be adjusted for each point on the graph. You can also set the length of time for the count.
Show Grid The Show Grid check box displays the data collected in the grid. The grid displays an ongoing collection of data based on the user selectable settings in the View > Preferences > Grid Settings dialog box. For example, if the grid setting is 60 seconds, a new data point will appear on the grid every minute. Observer USB Chart Screen The Observer USB Chart Screen displays a chart of the data currently collected by the attached instrument.
Chapter 8: Observer USB Calibration Software General Discussion of Calibration In order to have confidence in the measurements taken with a radiation detection instrument, a calibration must be performed. The calibration compares the response of the instrument to known values and the instrument is adjusted (if needed) to bring all indications within the range of the instrument to within ±10% of the true values. Generally, radiation detection instruments should be calibrated annually.
Efficiency Calibration The Inspector EXP can be used beyond simple detection of contamination and can also be used to determine the activity of any beta- or alpha-emitting isotopes present. Efficiency is the ratio of events detected by the instrument to the number of decays of the particular isotope. The units are therefore counts per disintegration of c/d. Since efficiencies are generally somewhat less than one, they are often multiplied by 100 and expressed as a percentage.
Procedure (Metric Units) 1. Power on the Inspector EXP. Make sure the Inspector EXP is in Timed Count (Total/Timer) mode displaying COUNTS. 2. Place the Inspector EXP in the location where the efficiency calibration will be performed and take a count of at least 10 minutes. Multiply the acquisition time by 60 to convert it from minutes to seconds. Divide the total number counts by the acquisition time (in seconds) to calculate the background counting rate (RB) in cps. Record this value. 3.
Exposure Rate Calibration An exposure rate calibration correlates the number of counts in a given time to the exposure rate present in that field. This is in many ways similar to efficiency but we refer to it in this case as gamma sensitivity. Although it is possible to express this value in several different units, the Inspector EXP uses a formula of CPM/mR/hr (counts per minute per milliroentgen per hour).
Chapter 9: Built in Isotope Efficiencies Built in Isotope Efficiencies The Inspector EXP has a number of built in efficiencies for specific isotopes. If you know the isotope being surveyed, then you can select one of the pre-programmed isotope efficiencies to calculate the activity of your known source. The activity (DPM and Bq) is different from the rates of exposure (mR/hr, µSv/hr, CPM, and CPS).
Chapter 10: Troubleshooting The Inspector is a highly reliable instrument. If it does not seem to be working properly, look through the following chart to see if you can identify the problem.
Chapter 11: Basics of Taking Measurements The Inspector EXP will not detect neutron, microwave, RF (radio frequency), laser, infrared, or ultraviolet radiation. All of our instruments are most accurate for Cesium-137 and isotopes of similar energies. Some isotopes detected relatively well by most Geiger counters are Cobalt-60, Technicium-99M, Phosphorous-32, Strontium-90, and many forms of Radium, Plutonium, Uranium, and Thorium.
Geiger counters can detect the four main types of ionizing radiation: alpha, beta, gamma, and x-rays. Some detect only gamma and x-rays. Our instruments are calibrated to Cesium 137, but also serve as excellent indicators for many other sources of ionizing radiation. Gamma and x-rays are measured in milliroentgens per hour (mR/hr), microsieverts (µSv/hr), or millisieverts (mSv/hr). Alpha and beta are measured in counts per minute (CPM) or counts per second (CPS). The window of the GM tube is very thin mica.
Radiation Measurement Units Several different units are used to measure radiation, exposure and dosage. Roentgen is the amount of X-radiation or gamma radiation that produces one electrostatic unit of charge in one cc of dry air at 0° C and 760 mm of mercury atmospheric pressure. One thousand milliroentgen (1,000 mR)= 1R. The Inspector EXP displays in milliroentgens per hour (mR/hr). Rad is the unit of exposure to ionizing radiation equal to an energy of 100 ergs per gram of irradiated material.
Chapter 12: Glossary of Common Terms Background Radiation Naturally occurring radiation is always present, it includes high energy gamma rays and particles from the sun and outer space and alpha, beta, and gamma radiation emitted from elements in the earth. CPM (counts per minute) The unit of measurement usually used to measure alpha and beta radiation. Ion An atomic particle, atom, or molecule that has acquired an electrical charge, either positive or negative, by gaining or losing electrons.
Appendix A: Technical Specifications RELATIVE COUNTRATE Detector Internal Halogen-quenched, uncompensated GM tube with thin mica window, 1.4-2.0 mg/cm2 areal density. Effective diameter of window is 45 mm (1.77 in.). Radiation symbol on front label and end panel marks the center of the detector. Averaging Periods Display updates every 3 seconds. At low background levels, the update is the average for the past 30-second time period.
Appendix B: Limited Warranty WARRANTOR: S.E. International, Inc., P.O. Box 39, 436 Farm Road, Summertown, TN 38483-0039, USA, (931) 964-3561 ELEMENTS OF WARRANTY: S.E. International, Inc., warrants for 90 days the Geiger-Mueller tube and for one year all materials and craftsmanship in this product to be free from all defects with only the limitations set out below.
Calibration Database Application Please fill out this form and send it back to us if you would like to be notified of the NIST calibration renewal for your instrument to: S.E. International, Inc. P.O. Box 39, 436 Farm Rd. Summertown, TN 38483 1.800.293.5759 | 931.964.3561 | Fax: 1.931.964.3564 www.seintl.com | radiationinfo@seintl.com NAME MODEL NAME COMPANY SERIAL NUMBER ADDRESS DATE PLACED IN SERVICE CITY EMAIL STATE, ZIP, & COUNTRY PHONE NUMBER Or fill out the form online at http://seintl.
