↳ The Multi-Wiper Series – Features

Wipe Testing – Only Faster

We know you are busy. We realize how valuable your time is, do you?

How many minutes a day do you waste standing in front of your well counter doing wipes one after another, after another, after another?

Would you like to be able to count 10 wipes at once? The Multi-Wiper does wipes in a whole new way. Using a Wipe Set you can create a room and test up to 16 different wipes test samples in that set. Each Wipe location can have its own trigger level and its own choice of isotopes to screen for. After a simple initial setup, your new Multi-Wiper is ready to provide you with fast, accurate wipe test reports – IN DPM- that will satisfy the most aggressive inspection. You will do it in less then 1/10th the time it takes you now.

How much does that add up to? Lets take a look.

If your Laboratory has 30 wipes to run only once a week and you count for 1 minute per wipe, you could spend over 30 minutes counting your wipes. With a 10 well Multi-Wiper you will spend only 3 minutes counting your 30 wipes. Over a five year period that is more than a 15 working day savings. Counting more often only multiplies your time savings!

Wipe Test Library

The Wipe Set Library is where you go to set up and/or run your wipe test routines. Up to 16 wipe sets may be programmed into the instrument. A wipe set is defined as any large area which may contain multiple locations for wipe testing. An example of a wipe set might be Room 1, within which the locations include Bench 1, Bench 2, Sink, etc.


The Count time is determined per Set, so all locations within the set will be counted for the same length of time. Each location has its own Isotope list so you may choose only one isotope, or scan multiple isotopes. Each isotope may have its own trigger level. Simply select the number of the isotope that you wish to modify and enter it.


The trigger levels are in CPM or DPM, dependent on the isotope efficiency as shown in the Isotope Library.

  • A) If an efficiency exists for an isotope the MULTI-WIPER will automatically use the calculated DPM value for comparison to the trigger selected.
  • B) If efficiency has not been selected, the MULTI-WIPER automatically uses the default value of 100% efficiency (DPM = CPM). CPM used for trigger.

Of course, you have the option of printing a comprehensive wipe test report. Since you have control of the printout, you may choose to report the status of all the isotopes- or only those that fail.


The first position in the Wipe Set Library is pre-programmed as General. General is designed to allow the user to quickly and easily run a wipe test without the need to program specifics into the system. General always runs the wipes under a full window, and will indicate the acquired counts in the various isotope windows.



The Multi-Wiper prints concise and informative full page reports. Below is a sample of a Wipe Test Report created using a room we called AREA1.

For AREA1, we set up three locations to be wipe checked. These locations were designated as: BENCH1, SINK1, and TABLE. The number of locations can be up to 16 for each designated Room.

Documentation includes, Date, Time, Count Time of samples and the calculation of the MDA (Minimum Detectable Activity) as shown.

Please note that some of the results are in DPM and several in CPM.

CPM is shown when there has not been an efficiency determined for that isotope. Background is shown for each isotope and is subtracted to show Net Activity. The PASS/FAIL result is determined by a comparison to the isotope trigger level (DPM or CPM) as set up in the location section.

As can be seen from the report (left picture), each location may be configured as to what isotopes are being looked for and their trigger levels.


In addition to the Wipe test report the Multi-Wiper has comprehensive reports for the built in invitro tests as well. Schilling, CPM, Red Cell Volume, GFR and Plasma Volume. Right picture is a sample of a Schilling test report.

Isotope Selection

The Multi-Wiper Series gamma counters utilize a NaI(tl) crystal detector. These detectors incorporate a mono-line well-type configuration, ensuring superior geometry and counting efficiency over traditional styles. The well is bored deeply to accommodate varying sample sizes with minimal loss of efficiency due to “angle of incidence”.

Each Multi-Wiper detector contains extra crystal mass at the bottom of the detector to allow better “stopping power” for higher energy isotopes. Greater efficiency is achieved than with traditional small diameter detectors. Two stage lead shielding provides excellent shielding. Lead between detectors and additional heavy lead plates surrounding the entire detector array provide low backgrounds for improved signal to noise ratio and superior counting results.

This unique crystal design enables the Multi-wiper to count high energy isotopes without the need for extremely large diameter detectors. Having many wells counting simultaneously, along with the high efficiency design of our crystals greatly increases the throughput.

Isotopes are Setup, Deleted, Edited and Normalized in the Isotope Library.


High energy isotopes emit radiation that can cross, even through lead shielding, to the adjacent detectors and contribute to the count rate measured by those detectors. The X-talk Correction feature removes this crosstalk effect, allowing the resultant counts in each detector to be true net counts.


One important application for this high energy capability is in the area of P.E.T. counting. The Multi-Wiper has a 4096 channel ADC, this give the Multi-Wiper 1/4 KEV resolution. The isotope window is set with an upper and lower window, in 1 KEV increments, up to 1000 KEV ( 2000 KEV for the HE Models). With this option, you can set a wide window to scan unknowns for any interfering isotopes.


The CPM test is just that; a mode in which to quickly and easily count samples to be reported as CPM. You may choose the count time, the source of data for the test, (wells, keypad, etc) the isotope measured and the display/print modes. Values are always reported as CPM. This test, CPM (counts per minute), is for counting a sample and selected isotope for specified length of time. with no other calculations done, other than background subtract. The format of all the tests shown has been unified such that each test input is similar. All calculations are already included and the results are presented in the report of each sample.


System Diagnostics

The Multi-Wiper has a series of built-in diagnostic programs that will help to troubleshoot a problem if one ever arrises.


Chi-Square: This statistical test is a goodness of fit test. Since radioactivity is a random phenomenon that follows a Poisson distribution, the Chi Square test automatically measures and validates that no deviation of the statistics is occurring.


Full Width Half Max: Select Co57 from the Isotope menu and insert the Co57 standards in each well, then press any key.


Printer test:. See example

This is a Printer Test 0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz 0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz 0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz

0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz 0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz 0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz

Note: This output is dependent on printer used.

The MULTI-WIPER automatically performs self diagnostics of its internal Random Access Memory along with additional static RAM tests.


Factory Calibration: This requires a special code input, for factory use only. Call LTI if you wish to use this feature as improper use can adversely affect your instrument.

Reset PRAM Memory: This function resets of the programmed memory. This feature should be used only under directions from LTI service.