I have 800va microtek inverter non sine wave.i want to know what is the output voltage available

Measure the true RMS output voltage and act upon your findings.

if not to old, return to suppliers need bench attention if readoutbis her than should dont run. possible possible fire hazard

It depends on what you are using to measure the voltage. Cheap meters can do this. You need a true RMS meter to read these properly. Most inverters use Modified Sine Wave technology which mimics a sine wave poorly and cheap meters do not respond well to the waveform. There is likely nothing wrong with the inverter.

That is normal because:
Vrms[full-wave]=Vm/sqr2
Vrm[half-wave]=Vm/2

test with Voltmeter True RMS

Are you using a true-RMS voltmeter to measure the DR's output? The DR's output is modified sine wave, and a cheap average reading AC voltmeter will give you a reading of 90 volts or so. Alternately, if you have an oscilloscope, you can verify that the modified sine wave is around 170V peak to peak. It should alternate in segments of -170, 0, +170, 0... The duty cycle and peak voltages will vary with the inverter load.
- Tom, Sun Electronics International, Miami, FL

The output of this inverter (and most others) is a modified sine wave, which isn't quite the same as a true sine wave - like you get from a wall outlet. Unfortunately, most transformers (which is essentially what your laptop power-supply is) require a true sine-wave. Your inverter will work fine for many other 110V applications. You can buy an inverter with a true sine-wave output, but they are more expensive.

What kind of inverter is it and what kind of meter are you using to check the voltage with? If the inverter puts out modified sine wave, you have to use a true rms volt meter to accurately check the voltage with. A non rms volt meter will show a low reading.

Get out of here!!!!

The rms voltage is what counts, because it tells how much power the output will deliver to a resistive load. Inexpensive multimeters on their AC ranges are usually average-responding rms-calibrated meters. This means they measure the average of the absolute value of the AC component of the signal, and display that average multiplied by about 1.11 (actually, pi over sqrt(8)), the ratio of rms to average value for a pure sine wave. That way, the meter will give the right rms reading for a sine wave.

If the signal is a square wave, where the average and rms values are equal, the average-responding meter will read 11% too high.

Many inverters put out a modified sine wave (MSW), which sits at zero for a while, goes to a constant positive level for a while, goes back to zero for a while, and goes to a constant negative level for a while to complete the cycle. The positive and negative parts of the signal have the same magnitude and duration.

The rms and average values of an MSW depend on its duty cycle D, the fraction of a cycle for which the signal is not at zero. In a well-designed inverter, the duty cycle will be adjusted when the DC input voltage goes up and down to maintain the nominal rms output voltage. If we use peak voltage Vp to mean the magnitude of the positive and negative voltages the signal goes to, then Vavg for an MSW is equal to Vp times D, and Vrms is equal to Vp times the square root of D.

The duty cycle for which an MSW will have the same rms to average ratio as a sine wave is 8 over pi squared, or 81%. For any duty cycle less than this, an average-responding meter will read a lower voltage than the inverter rms output, and for a duty cycle higher than this, the meter will read too high.

If your MSW inverter is putting out 120 volts rms and its duty cycle varies from 50% to 75%, the meter reading will vary from 94 volts to 115 volts. I avoid the problem by using a Radio Shack 22-174B true rms digital multimeter.