Bs En 60268

[Niklas Terki]

Variouslysates were subjected to SDS PAGE followed by western blot with 60268-1-Ig (PKM2-specific antibody) at dilution of 1:20000 incubated at room temperature for 1.5 hours. The membrane was stripped and reblotted with HRP-conjugated GAPDH Monoclonal antibody (HRP-60004) as loading control.

PKM, also named as OIP3, PK2, PK3, PKM, p58, THBP1, CTHBP and Tumor M2-PK, belongs to the pyruvate kinase family. It is glycolytic enzyme that catalyzes the transfer of a phosphoryl group from phosphoenolpyruvate (PEP) to ADP, generating ATP. It stimulates POU5F1-mediated transcriptional activation. PKM plays a general role in caspase independent cell death of tumor cells. PKM has 2 isoforms,the activity of the M2 isoform can be inhibited by tyrosine kinase signalling in tumourcells. The immunogen of this antibody is M2 isoform and this antibody is specific to PKM2 isoform.

At Proteintech, we pride ourselves on our antibody quality, customer service and transparency. As such, we are comparing our antibodies with other vendors, enabling easy identification and comparisons of key data to help you choose the suitable antibody for your needs.

The first KLIPPEL LIVE series have started with a 15 part web-seminar about using the IEC 60268-21 acoustical measurement standard, perfect for anyone working with speakers, headphone and other audio devices.

This application note describes how to test audio amplifier audio characteristic using the audio analyzer R&S UPV in accordance with standard IEC 60268-3. The test items include gain, frequency response, harmonic distortion, modulation distortion, difference-tone intermodulation, dynamic intermodulation distortion, noise and cross-talk. The test items are explained and the test steps are described in detail.

DIM stands for Dynamic InterModulation distortion. It is a technique used to measure the non-linearity of a device, and it's designed to be particularly sensitive to distortions produced during transient conditions typical of audio program material. In DIM measurements, a square wave at a frequency of 3.15 kHz is low-pass filtered and then linearly combined with a sine wave at a frequency of 15 kHz. DIM 30 and DIM 100 use single-pole low-pass filters with cutoff frequencies of 30 kHz and 100 kHz, respectively.

If non-linearities are present, the DIM signal induces intermodulation distortion products at nine difference frequencies ranging from 0.75 kHz to 13.35 kHz. DIM is then calculated as the ratio of the root mean square (RMS) sum of the levels of the nine intermodulation components to the level of the 15 kHz sine wave. It is typically expressed as a percentage or in dB.

An analog domain Audio Precision 2700 series analyzer equipped with the IMD option has the ability to generate DIM 30 and DIM 100 waveforms. But the DIM measurement provided by the system's Analog Analyzer is just an approximation of the DIM level specified by IEC 60268-3, because it only considers two of the nine intermodulation components specified in the standard. A DIM measurement that conforms exactly to IEC 60268-3 can be conducted using the DIM generator in conjunction with the FFT analyzer available in DSP-equipped systems (2712 and 2722). This zip archive contains an AP2700 Basic macro that will conduct DIM 30 and DIM 100 measurements per IEC 60268-3.

The macro works as follows: First, it checks to see if the panels are set up as outlined above. If they are not, the macro displays an error message and then exits. Next, the macro reads the sweep parameters from the sweep panel, conducts an FFT-based DIM measurement for each step in the sweep, calculates the DIM levels according to IEC 60268-3, inserts the DIM results into the Data Editor panel (Figure 4) and plots them in the Graph panel (Figure 5). Finally, the macro reverts the Sweep Panel to the setup it had before the macro was run.

Since our founding in 1984, Audio Precision (AP) has evolved into the worldwide leader for audio analyzers and audio testing. We maintain a singular focus: to help engineers worldwide design, validate, characterize, and manufacture audio components, products and systems.

Fast forward thirty-plus years and AP is the recognized global standard in audio tests. We provide elite audio analysis, audio measurement software, and a wide range of modules, options and accessories to support analog and digital audio measurement, as well as electro-acoustic testing, and much more.

In professional use, which requires consistent level measurements across an industry, audio level meters often comply with a formal standard. This ensures that all compliant meters indicate the same level for a given audio signal. The principal standard for PPMs is IEC 60268-10. It describes two different quasi-PPM designs that have roots in meters originally developed in the 1930s for the AM radio broadcasting networks of Germany (Type I) and the United Kingdom (Type II). The term Peak Programme Meter usually refers to these IEC-specified types and similar designs. Though originally designed for monitoring analogue audio signals, these PPMs are now also used with digital audio.

In common with many other types of audio level meter, PPMs originally used electro-mechanical displays. These took the form of moving-coil panel meters or mirror galvanometers with demanding 'ballistics': the key requirement being that the indicated level should rise as quickly as possible with negligible overshoot. These displays require active driver electronics.

Nowadays PPMs are often implemented as 'bargraph' incremental displays using solid-state illuminated segments in a vertical or horizontal array. For these, IEC 60268-10 requires a minimum of 100 segments and a resolution better than 0.5 dB at the higher levels.

Many operators prefer the moving-coil meter type of display, in which a needle moves in an arc, because they feel the angular movement is easier for the human eye to monitor than the linear movement of a bar graph.[3]

A variety of terms such as 'line-up level' and 'operating level' exist, and their meaning may vary from place to place. In an attempt bring clarity to level definitions in the context of programme transmission from one country to another, where different technical practices may apply, ITU-R Rec. BS.645 defined three reference levels: Measurement Level (ML), Alignment Level (AL) and Permitted Maximum Level (PML). This document shows the reading corresponding to these levels for several types of meter.[4] Alignment Level is the level of a steady sine-wave alignment tone. Permitted Maximum Level refers to the permitted maximum meter indication that operators should aim for on speech, music etc., not tone.

Quasi-PPMs use a short integration time so they can register peaks longer than a few milliseconds in duration. In the original context of AM radio broadcasting in the 1930s, overloads due to shorter peaks were considered unimportant on the grounds that the human ear could not detect distortion due to momentary clipping. Ignoring momentary clipping made it possible to increase average modulation levels. In modern digital audio practice, where quality standards are hopefully much higher than AM radio in the 1930s, clipping of even short peaks is usually regarded as something to avoid.

On typical, real-world audio signals, a quasi-PPM under-reads the true peak by 6 to 8 dB.[5] Nevertheless, quasi-PPMs are still widely used in the digital age because of their usefulness in achieving programme balance. Overloads are avoided by allowing, typically, 9 dB of headroom when controlling digital levels with a quasi-PPM.

The extent to which quasi-PPMs show less than the true amplitude of momentary peaks is determined by the 'integration time'. This is defined by IEC 60268-10 as, "...the duration of a burst of sinusoidal voltage of 5000 Hz at reference level that results in an indication 2 dB below reference indication."[6][7] This standard also contains tables showing the difference between indicated and true peaks for tone bursts of other durations. The longer the integration time, the greater the difference between the true and indicated peaks.

All PPMs have a return time much longer than the integration time, to give the operator more time to see the peaks and reduce eye strain. Type I PPMs fall back 20 dB in 1.7 seconds. Type II PPMs fall back 24 dB in 2.8 seconds.

The PPM was originally developed, independently in both Germany and the United Kingdom, for use in AM radio broadcasting networks in the 1930s. These were quasi-peak meters with some features in common but otherwise substantially different. They are superior to earlier types of meter that were not good for monitoring peak audio levels.

In about 1936 and 1937, German broadcasters developed a peak programme meter with a mirror galvanometer known as a "Lichtzeigerinstrument" (light pointer) for the display. The system consisted of a drive amplifier (e.g., ARD types U21 and U71) and a separate display unit (e.g., ARD types J47 and J48).[9] A stereo version, known as a "Doppel-Lichtzeigerinstrument" contained two mirror galvanometer displays in a single housing. Such displays were still used until the 1970s, when solid-state bargraph displays became the norm.

The design became standardised as DIN 45406. It evolved into the Type I meter in IEC 60268-10 and it is still known colloquially as a DIN PPM. Compared to the Type II designs it has faster integration and return times, a much wider dynamic range and a semi-logarithmic scale, and is calibrated in dB relative to Permitted Maximum Level. It remains in use in much of northern Europe.[10]

In Scandinavia a variant of the DIN PPM known as 'Nordic' is used. It has the same integration and return times but a different scale, with 'TEST' corresponding to Alignment Level (0 dBu) and +9 corresponding to Permitted Maximum Level (+9 dBu).[3][10][11] Compared to the DIN scale, the Nordic scale is more logarithmic and covers a somewhat smaller dynamic range.

3a8082e126