Tel: +86-13302916851

China Shenzhen Baichuan electronics Co., LTD

Professional manufacturer of acoustic test instruments.





A pen-like bar. Before using, the user must pull back the upper half portion of
the probe’s protector, to emerge the sensor chip for testing, right after the
testing, the user must pull back the probe’s protector to its original position, to
prevent damage to the sensor chip.
NOTE :User must hold gently the upper both sides of the probe’s protector, then, gently
pull backward the probe’s protector, never press the tip end of the probe’s
protector to press backward the upper half portion of the probe’s protector,
since this will damage and break the sensor chip. Please refer to the following

Technical specification:

1、Digital Display: 3 1/2 digits, Resolution: 1 gauss.

2、Measuring Range: 0∼20.0K gauss, autoranging. Two ranges: 0∼2.0K, 2.0K∼20.0K gauss.

3、Accuracy (probe excluded):

Normal : ±(0.1% Rdg.+ 0.05% FS)

Peak hold : ±(0.2% Rdg.+ 0.1% FS)

(1/4) x 4 : ±(0.3% Rdg.+ 0.1% FS)

4、Peak hold decay < -0.05% /sec.

5、Accuracy ( probe included ) :

At 10K gauss : ±1.7%
0∼15K gauss : ±(2% Rdg.+ 0.1% FS)

15∼20K gauss : ±2.5%

6、Dim. : 14 (L) x 22.5 (H) x 23 (D) cm.

7、Net Weight : 2.8 KGS.

  • Product Detail
  • Features
  • Usage
  • After-sales services

138A Gauss Meter is exclusively used to test the flux density of all kinds of magnetic components. Regardless what its material or the shape of magnet is, Model-138A can test its flux density.

For example: Ferrite Magnets、Flexible Rubber Magnets 、Rare Earth Magnets、Alnico Magnets…can all be tested by Model-138A. Also, Magnets for loudspeaker、headphone、microphone magnet、motor and relay, as well as other magnetism components can all use Model-138A to test its flux denstity.138A is especially designed with “Peak Hold” & “Auto Accumulating and Auto-Averaging” two functions, especially suitable to test the flux density of the magnetic gap of loudspeaker 、headphone and microphone…etc.

1、Peak Hold

To use a Gauss meter without the “Peak Hold” function“ for testing the flux density, due to the unsteady vibration of the Gauss Meter’s needle or the unstable displayed value in course of testing , it is hard to obtain the real “Peak Value”. Model-138A has the “Peak Hold’ function which can test the “Peak Value” easily. If user used a Gauss meter without the “Peak Hold” function to test the flux density in magnetic field, then, he must observe the test value and adjust the testing position simultaneously in course of testing, so to obtain the biggest (ideal) value, in this case, user has to repeat numerous testing, consequently, sensor chip of the probe might got abrasive easily, moreover, it might got broken due to distraction of the user.

2、Auto Accumulating and Auto-Averaging

To test the flux density of the magnetic gap, user must sum up the peak value at the 4 points magnet gap, and divide the total peak values by 4, to get the average peak value. If used a conventional Gauss Meter, user must record down the 4 tested peak values, and compute the average peak value manually, this is inconvenient and time-consuming. 138A is a unique design with “4 times auto accumulating & averaging” functions, rapid test & accurate result.

Model-138A has the following three kinds of test modes: (1) NORMAL;(2) PEAK HOLD (which is 1/1 x one time testing);(3)1/4 x 4 four times testing. Detail description as follows:

Model-138A has the following three kinds of test modes: (1) NORMAL;(2) PEAK HOLD (which is 1/1 x one time testing);(3)1/4 x 4 four times testing. Detail description as follows:


Let pushbutton be at press out position, the displayed value is the Gauss value of the tested point. The Gauss value will vary from the changing of the testing point or the density of flux.

2、PEAK HOLD ( 1/1 x 1,one time testing ) :

Press in pushbutton 6, and press once “RESET” pushbutton, to let the displayed be at “000”, then, user can perform testing. The tested value only stops at the highest flux density value and held it, unless a higher flux density value is tested, such tested highest flux density value will remain unchanged, although user has removed the probe away from the magnetic field, the tested peak value will not be changed. To start a new testing, user must press “RESET” pushbutton.

3、1/4 x 4 four times testing:

For testing the uneven magnetic field, we usually used the “Averaging” method, which is by testing the flux density of some testing points, add the results and get the average, in order to get a more precise value. Especially for the flux density in the gap of loudspeaker、headphone、microphone magnet , for the same magnet , some gap is wider, its flux density becomes smaller; while some gap is narrower, its flux density becomes larger, if using the averaging method, the tested result is precise and objective. Before using, user must first press in pushbuttons (6) and (8), and press once “RESET” pushbutton. For detail usage and steps, please refer to item 8 of the previous page.

20 years industry experience

24 hours Technical Support

Professional engineers on line response

All life Costs Maintenance



Leave a Reply

Leave a message