THDP-TMDP_Instructions-077054003.pdf - 第17页

The remaining controls and features of the probe are located on the probe head. Probe inputs The maximum voltage that the probe inputs can accept depend on the probe model and the measurement points. For example, the THD…

Probe release button

Press the release button to unlatch the probe from the instrument, and then pull the probe straight out.

WARNING: T

o avoid electrical shock, disconnect the probe inputs from the circuit before disconnecting the probe from the

instrument.

Status LED

When the probe is connected to the instrument, the Status LED lights amber as the probe completes a self-test. Then, the Status LED

goes of

f briefly and then lights green to indicate the probe is ready to use.

The Status LED lights amber or red if the power-on test failed, or any time an error occurs. If the Status LED light does not light green after

the self-test, first disconnect the probe from the circuit under test, and then disconnect the probe from the oscilloscope.

Reconnect the probe to the oscilloscope and check that the Status LED lights amber, and then green. If the Status LED continues to light

amber or red, there may be other remedies. See Error conditions on page 61.

Menu button

Press the MENU button to display on-screen probe controls on the oscilloscope. Many probe functions are available, such as AutoZero

and range selection.

Probe operating information

The remaining controls and features of the probe are located on the probe head.

Probe inputs

The maximum voltage that the probe inputs can accept depend on the probe model and the measurement points.

For example, the THDP0200 probe (shown) can measure a maximum of 1,000 V

RMS

T II between either input and ground, and a

maximum difference of 1,500 V (DC + peak AC) between the (–) and (+) inputs. These input ratings are valid for both range settings.

The other probes covered in this manual have different limits; refer to Specifications.

CAUTION: Do not use these probes above the input limits shown on the probes. The input voltage limits vary by probe model.

Overrange indicator

The OVERRANGE indicator lights red if the voltage of the input differential signal exceeds the linear range of the range setting. When this

happens, the signal on the probe output does not accurately represent the signal on the probe input.

WARNING: The Overrange indicator does not detect overrange condition of common-mode voltages or voltage-to-earth potential

at the probe inputs. The Overrange indicator only detects dif

ferentially between the + and – inputs (not relative to ground).

Do not exceed the common-mode voltage or input voltage-to-earth ratings of the probe when taking measurements. See

Overrange detection on page 37.

If you are not sure, make a single-ended measurement of each point you are intending to measure differentially first. Make a

single-ended measurement by tying one input lead to ground (the "–" input) and then connecting the other lead (the “+" input) to

the points of interest, one at a time.

Voltage range button and indicators

Press the RANGE button to select between the voltage range (attenuation) settings of the probe. The voltage range is indicated by two

LEDs on the probe and may be displayed on the oscilloscope screen, depending on the oscilloscope model.

The OVERRANGE LED lights if the applied voltage exceeds the selected range. T

o extinguish the LED, select a higher range. If a higher

range is not available, do not attempt to take the measurement with the probe.

Probe operating information

High Voltage Differential Probes THDP0100/0200 and TMDP0200 User Manual 17

Bandwidth limit button and indicators

Press the BANDWIDTH LIMIT button to limit the probe bandwidth to 5 MHz. 5 MHz is close to the switching frequency of most switching

transistors (FET

s) in switch mode power supplies (SMPS).

The 5 MHz filter assists in the characterization and testing of power supplies in switch mode by removing all high frequency content, noise

and harmonics from the measurement.

Press the button again to return to the FULL position, which selects the full specified bandwidth of the probe.

Audible overrange on/off button and indicators

The audible overrange is an audible alarm that indicates when the measured signal exceeds the selected range. The alarm is enabled

when the probe is first powered on.

Press the AUDIBLE OVERRANGE button to light the OFF LED and disable the feature. T

o enable the alarm, press the button again to light

the ON LED.

Probe operating information