- Display
- Four windows, four-digit high-brightness LED
- Input voltage
- 3 to 360 V AC on the selection table; 3 to 600 V on the parameter page, both carried
- Input current
- 5 mA to 20 A on three models; 5 mA to 2 A on the two small-current models
- Accuracy
- 0.5 class, as stated in the material
- Power factor range
- -1.000 to 1.000
- Frequency
- 45 to 65 Hz on alternating current
- Update time
- 0.2 s per reading
- Limit comparison
- Upper and lower limits with a buzzer, on four of the five models
- Interface
- RS-232 or RS485, listed as optional
- Supply and body
- Not stated in the material
A bench instrument for electrical parameters is judged by what it shows at a glance and by whether it can reject a part without a person watching it. This range answers both, in five models that differ in three respects only.
Product overview
All five models share one measuring engine and one four-window display. What changes between them is whether a direct-current input is accepted, how much current the input can carry, and whether the instrument compares the reading with limits and signals the result.
That last difference matters more than it looks. Two models indicate only, in the sense that they will show an out-of-limit reading but cannot buzz or light a lamp for it, and the entry model has no comparison at all. A test position that depends on an operator noticing a number is a different proposition from one that stops the line by itself.
The instrument is built as a bench case with the display on the left and the keypad on the right, and it is intended to sit beside the item under test rather than to be panel mounted.
How the meter works
Voltage across the load and current through it are sampled together by the internal microcontroller and multiplied point by point. Averaging that product over a whole number of mains cycles gives active power without assuming that the load is resistive or that the waveform is a clean sine wave. Power factor is then the ratio of that active power to the product of the root-mean-square voltage and current, and the remaining quantities follow from the same samples.
Both input channels change range automatically. That is not a convenience so much as an accuracy measure: the reading is taken on the range that suits the signal, rather than on whichever range happened to be set when the instrument was last used, which is the commonest source of a wrong figure on a shared bench.
Four windows carry voltage, current, power and power factor, which are the four quantities a production test usually needs at once. Frequency is also listed among the displayed quantities, and the material does not say which window it shares.
How to select the right model
The first question is whether any part of the duty is direct current. An adapter, a charger, a DC supply or a battery forces one of the two models with a direct input; no setting on the alternating models will substitute for it.
The second is current. The 20 A input covers mains appliances, heaters and small motors, while the 2 A input is for products whose working current is small enough that a high range would lose resolution at the bottom. The two small-current models are also the two that accept direct current, so a low-power DC product is served by one model rather than by a combination.
The third is whether the instrument has to reject. If a buzzer or a pass indication is part of the test, the entry model is excluded however well it measures. Serial communication, where it is wanted, is a fourth decision taken at order.
Measurement limitations and selection considerations
The accuracy class is a statement about the instrument under reference conditions. In service the figure also depends on the range in use, the power factor of the load, the crest factor of the current and the way the instrument is connected, and the material states no error limit for those conditions. A class figure alone therefore does not predict how a particular test will go.
The material states that waveform distortion does not affect the reading, but it does not describe the conversion behind that statement. Where a load is a switched-mode supply, a phase-angle controller or a drive, the difference between a true root mean square conversion and an average of the rectified waveform is the difference between a correct figure and a plausible one, and it should be confirmed rather than assumed.
This instrument reports the operating point; it does not explain it. Harmonic content, flicker, unbalance and transients belong to a power quality analyser, and energy over a long run is not accumulated here. Where the question is why a figure is what it is, a different instrument is required.
Two practical points remain open in the material and should be settled before a bench is laid out: the body dimensions and the input terminals at the rear, neither of which is described. The supply voltage is likewise unstated, which matters for a destination outside the usual mains range.
Every value below is taken from source documentation. Where a parameter is not stated in the available material it is marked as information required rather than estimated.
