Portable Fluxgate Magnetometer

It is suitable for testing weak constant magnetic fields, magnetic fields in magnetic shielding devices, magnetic field values ​​generated by magnetic measuring tool coils, and residual magnetism of materials. It can directly test the earth's magnetic field components and their slight changes with six-digit magnetic field values, and can also be used as a standard magnetometer to calibrate low-precision magnetometers. And it can output data through the RS-232 interface. The instrument is simple to operate, reliable in operation, and easy to carry.

The main performance indicators of CTM-6W fluxgate meter are as follows:

1. Measurement magnetic field range: ± 99999.9 nT (1Gs)
2. Static noise: <0.2 nT (p-p)
3. Residual magnetic bias: <10nT
4. Accuracy: 0.05% ± 10nT
5. Magnetic field display: LED six-digit
6. RS232 optical isolation serial code output
7. Zero compensation - no need to adjust the compensation current in the measurement state, just press the zero offset key to set any point in the full range to zero
8. Warm-up time: 15min
9. Power supply: 12 V lithium battery inside the machine or an external charger
10. Dimensions - Probe Φ8mm×50mm; Chassis 130×170×55mm

Instructions and precautions:

1. Insert the probe into the probe socket on the front panel, press the power switch on the rear panel, and the value displayed on the digital display on the front panel is the magnitude of the axial magnetic field of the probe. For example, "H-98765.4" nT is displayed, and "H" indicates the normal measurement of the magnetic field state. Press the power switch on the rear panel again to turn off the instrument.
2. When the header sign is displayed as a "-" number, it indicates that the direction pointed by the probe is opposite to the projection direction of the magnetic field on the axial direction of the probe. When the header sign is displayed as a positive number (no "+" sign), it indicates that the direction pointed by the probe is the same as the projection direction of the magnetic field on the axial direction of the probe.
3. Press the "Zero" button on the front panel lightly to change the display to "P 00000.0", which is equivalent to offsetting the reading to zero. "P" indicates that it is in a biased state in order to measure small changes in the relative magnetic field base value. Press this button again, and the instrument will cancel the bias and return to the normal measurement state. This method can repeatedly change the working state of the instrument.
4. The instrument has a 9-pin standard RS232 interface on the rear panel. It uses 8-bit asynchronous communication—8 data bits, 1 start bit, 1 stop bit, no parity check, and a baud rate of 19200. Data is output in ASCII code. When using a computer to read magnetic field data, please set the serial port parameters first. Please enter the "s" character when starting data transmission, and enter the "q" character when you need to stop data transmission. The following is an example of BASIC program reading data:

   10 OPEN "COM1:19200,N,8, ,CS0,DS0" FOR INPUT AS #1

   20 OUTPUT #1, "s"

   30 INPUT #1,S

   30 PRINT S

   40 END

5. The internal battery can work continuously for about 15 hours. When the battery is exhausted, the digital tube will automatically turn off. The charger can be plugged into the rear panel socket to charge the battery, and the charger can also supply power to the instrument. The charger still charges the battery when the power switch is off.

Application example:

When using a single-component fluxgate magnetometer to measure the weak magnetic field in a magnetic shielding tube, the magnetometer's display reading is the composite value of the magnetic field in the tube and its own residual magnetism because the magnetometer itself has zero-position residual magnetism. The method to accurately measure the magnetic field in the shielding tube and eliminate the zero-position residual magnetism of the magnetometer is as follows:

Place the magnetometer probe in the shielding tube so that the axis of the probe coincides with the axis of the shielding tube, record the magnetometer reading B1 at this time, and then rotate the probe 180°, and record the magnetometer reading B2 at this time. Note that B1 and B2 should contain the sign displayed by the magnetometer. The magnetic field value in the shielding tube is (B1-B2)/2, and the zero-position value of the magnetometer is (B1+B2)/2.

Precautions:

1. The probe and the host should be handled with care, and do not squeeze, bump, or drop.
2. Keep the probe away from strong magnetic fields to prevent the probe from being magnetized.
3. The probe and the host are used together and cannot be replaced at will.
4. The charger should use the dedicated charger that comes with the machine.
5. To ensure battery life, charge it at least once a month.