Multifunctional Level Meter
LM-321
This is a hand-held type multifunctional level meter equipped with functions required for the testing and maintenance of voice-band transmission lines, transmission equipment, and communication devices.
Equipment Category
Measuring instruments for transmission characteristics
Power supply
AC adaptor, AA batteries
Consisting of an oscillator, level meter, DC voltmeter, AC voltmeter, and ohmmeter, this hand-held meter is capable of high performance.
The measured values can be directly read through the digital display, and the peak hold function allows the retention of maximum and minimum values, thereby allowing the meter to be used for checking fluctuation ranges and other applications.
* The peak hold function can be used for measurement using the DC and AC voltmeters and the ohmmeter.
The single frequency measurement function allows the measurement of control signals, etc. through the answer and single tones of facsimiles and modems.
Measuring the answer tones allows the measurement of incoming call levels of devices at opposite ends of the line such as facsimiles and modems.
Capable of LM-321 to LM-321 calls through 4-wire leased lines, eliminating the need for providing a separate telephone line when testing such a call.
Configuration example
Main Specifications
| Standards | ||
| Item | Specifications | |
| Level meter | Input impedance | 600 Ω (balanced) (within 600 Ω±2%)/HIGH (50 kΩ) * within the measured frequency band |
| Measurement frequency range | 80Hz～25kHz | |
| Measurement level range | -60 dBm to +10 dBm (↑↓: key with a display indicating overflow/underflow)/Resolution: 0.1 dB | |
| Level measurement accuracy |
80Hz～300Hz：within±1.0dB 300Hz～4kHz：within±0.5dB |
|
| Absolute maximum input level | +20dBm | |
| Frequency counter | 80 Hz to 25 kHz/Display resolution: 1 Hz/Counting error: within ±2 Hz (when counting the cycles in a sine wave) | |
| Others | In the HIGH-Z mode, it can be connected to a general subscriber line | |
| Oscillator | Output impedance | 600 Ω (balanced) (within 600 Ω±10%) * within the output frequency band |
| Output frequency | 200 Hz to 25 kHz; MANUAL: Setting resolution: 10 Hz STEP1：0.3/0.6/0.8/1.0/1.3/1.5/1.8/2.0/2.5/3.0/3.4 kHz STEP2：0.2/0.3/0.4/0.6/0.8/1.0/1.5/2.4/3.0/3.4/3.5 kHz |
|
| Output level | -50 dBm to +5 dBm/Setting resolution: 1 dB | |
| Output frequency accuracy | Within ±0.01% | |
| Output level accuracy |
200 Hz to 300 Hz: within ±0.5 dB; 300 Hz to 4 kHz: within ±0.2dB 4 kHz to 10 kHz: within ±0.3dB 10 kHz to 25 kHz: within ±0.5dB |
|
| Signal purity | Overall distortion factor: 40 dB or higher (300 Hz to 3.4 kHz/under 0 dBm output power) | |
| Distorted waves: 4 kHz to 8 kHz: p-30 dB or lower; 8 kHz to 12 kHz: p-50 dB or lower 12 kHz to 50 kHz (in each 4-kHz band): p-60 dB or lower; ＊ p: 1 kHz/0 dBm |
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| DC voltmeter | Measurement voltage range |
0 to ±300 V (↑↓: key with a display indicating overflow/underflow)/resolution: |
| Measurement accuracy | Within ±(0.5% rdg±2 dgt) | |
| Input resistance | 5 MΩ or higher | |
| Absolute maximum applied voltage | 500 V (DC/AC) | |
| AC voltmeter | Measurement voltage range | 0 to 300 V/(↑: key with a display indicating overflow)/Display resolution: 1 V |
| Measurement accuracy | Within ±(2% rdg±2 dgt) | |
| Input resistance | 5 MΩ or higher | |
| Absolute maximum applied voltage | 500 V (DC/AC) | |
| Ohmmeter | Resistance measurement range | 0 to 3MΩ/(↑: key with a display indicating overflow)/resolution 0Ω～999Ω、1.000kΩ～3.299kΩ：1Ω 3.3kΩ～32.99kΩ：10Ω 33.0kΩ～329.9kΩ：100Ω 330kΩ～999kΩ、1.000MΩ～3.000MΩ：1kΩ |
| Measurement accuracy | Within ±(2% rdg±2 dgt) | |
| Absolute maximum applied voltage | 450 V (DC/AC) | |
| Continuity check | Buzzer sounds at a resistance below 200 Ω | |
| Peak hold function | After the function is turned ON, the maximum and minimum values of the displayed values are retained | |
| Single frequency measurement function | 300 Hz to 24 kHz/Setting resolution: 10 Hz; Detected frequency range: set frequency±50 Hz Counting error: ±5 Hz; Detection time: continuously 1,500 msec or longer |
|
| Call function | Capable of making calls through a 4-wire leased line | |
| Monitor speaker | Capable of monitoring input signals to the level meter (AGC with a volume switch) | |
| Power supply | AA batteries (1.5 V) × 4/The AC adaptor (ACP-311M) can be used | |
| Guaranteed temperature/humidity performance | Temperature: 0°C to 40°C; Humidity: 20% to 85% (Note: in an environment with no condensation) | |
| Dimensions/mass | Dimensions: D90 × H32 × W195 mm (The projection is not included)/Mass: 500 g or less (batteries not included) | |
