Math Buttons
| Null | Starts relative mode. IVI Soft Front Panels—DMM makes all subsequent measurements relative to the measurement it makes when you click Null. |
| Max/Min | Displays the maximum and minimum values that occur after you click Max/Min button. |
| dB | Compresses a large range of measurements into a much smaller scope by expressing DC or AC voltage in decibels. The relationship between dB and voltage is defined by the following equation: Vin dB = 20 log -------- Vref where: Vin is the DC or AC signal. Vref is the specified voltage reference level. This value is specified in the "dB, %Ref" field in the DMM Settings—Math dialog box. |
| dBm | Shows decibels above or below a 1mW reference. With a user-defined reference
impedance, IVI Soft Front Panels - DMM reads 0 dBm when the voltage needed to dissipate 1mW through the reference
impedance is applied. The reference impedance (dBm Zref) is entered under the Math tab of the settings window. The relationship between dBm, a reference
impedance, and the voltage is defined by the following equation: (Vin2 / Zref) dBm = 10 log ---------------------- 1mW where: Vin is the DC or AC input signal. Zref is the specified reference impedance. This value is specified in the "dBm Zref" field in the DMM Settings—Math dialog box. |
| mX+B | Enables the mX+B calculation on all readings. The Mx+B operation allows you to manipulate normal display readings (X) mathematically according to the following
equation: Y = MX + B where: X is the normal display reading. M and B are user-defined constants for multiplier and offset. Y is the displayed result. These values are specified in the "Mx+B Scaling" field in the DMM Settings—Math dialog box. |
| % | Selects the percentage calculation. IVI Soft Front Panels-DMM expresses the displayed reading as a percent deviation from the reference value entered in the DMM-Math Settings dialog box.
The percentage calculation is performed as follows: Input - Ref Percent = --------------------- x 100% Ref where: Input is the normal display reading. Ref is the user entered constant. Percent is the displayed result. Ref value is specified in the "dB, %Ref" field in the DMM Settings—Math dialog box. |