TDR-901 reflectometer open in its orange hard case, the 7-inch screen showing a trace above a row of soft keys and a rotary dial.

In its hard case, lid open: 7-inch touch screen, soft keys and rotary dial.

TDR-901 Time domain reflectometer

Battery-powered reflectometer that measures the distance to a cable fault in metres, before the surge generator and the pinpointer go out.

Range: 100km
Sampling: 200MHz
Battery: 7h
Weight: 3.5kg

Datasheet (PDF) 2 pages, English

Where it fits

The TDR-901 is step 1. It gives the distance that the surge generator and the pinpointer then work towards.

1
Step 1: Pre-locate
You are here
- TDR-901 Time domain reflectometer
- ARM Filter Arc reflection filter
2
Step 2: Condition
- PG-10 Surge generator, 10 kV
- PG-32 Surge generator, 30 kV
3
Step 3: Pinpoint
- AP-01 Acoustic pinpointer
4
Step 4: Trace route
- CRT-015 Cable route tracer

Overview

The TDR-901 sends a low-voltage pulse into the cable and times the echo. An open circuit, a short circuit or a joint shows on the trace as a reflection, and the instrument turns the delay into a distance in metres. It samples at 200 MHz over a range of up to 100 km.

A high-resistance fault does not reflect a low-voltage pulse. For those, the TDR-901 works with a surge generator: through the ARM Filter for arc reflection (ARM), or with the impulse current coupler for the impulse current method (ICM). Gain is adjustable, and traces are stored inside and copied to a computer over USB.

The 7-inch touch screen stays readable in sunlight, with soft keys and a rotary dial beside it. The internal battery lasts up to 7 hours. The instrument weighs 3.5 kg and sits in an orange hard case with a gasketed lid and two latches.

Specifications

Values from the product datasheet. Panel details as seen on the unit.

Measurement

Test methods	TDR, ARM, ICM
Measuring range	100 km
Sampling frequency	200 MHz
Gain	Adjustable

Display and data

Display	7 in touch screen, readable in sunlight
Controls	Soft keys under the screen, rotary dial, power key
Memory	Internal, for stored traces
Computer link	USB, port on the panel

Connections

Test lead	Screw-lock socket on the panel

Power and environment

Battery	Internal, rechargeable, up to 7 h
Input supply	AC 185 to 230 V, 50 to 60 Hz
Operating temperature	−10 to 40 °C
Relative humidity	5 to 90 %
Protection class	IP43

Mechanical

Dimensions (H × W × L)	81 × 218 × 274 mm
Weight	3.5 kg
Body	Plastic
Case	Orange moulded hard case, gasketed lid with two latches

Service

Calibration	Approval and certificate supplied

In the box

From the datasheet.

USB cable for data transfer
Cable to the short-gap filter
Filter
Charging cable
Touch pen
Carrying case

The TDR-901 open with its kit: a test lead in the front socket, red and black clip leads, a mains adapter and an orange impulse current coupler with its cable. — As photographed. The clip leads, mains adapter and impulse current coupler are not named on the datasheet list: ask us whether your quote includes them.

Works with

Alone, the TDR-901 finds opens and shorts. A high-resistance fault needs a surge generator as well, joined to the reflectometer through the ARM Filter.