Solutions for Fluid Technology FLOW MEASUREMENT TECHNOLOGY VHM SERIES FLOW MEASUREMENT TECHNOLOGY

We have developed a high precision flow meter for a wide variety of liquids, especially liquids with high abrasiveness and poor lubricity. Applications include: chemical, petrochemical, pharmaceutical and cosmetic industry, two-component mixers, paints, aviation. VHM flow meters are dead space optimised for use in the paint industry and for paint spraying systems (easy flushing). TECHNICAL DATA They are positive displacement units based on the meshing gear principle. Each tooth generates an impulse by recognition of the gear rotation by a non-contact detection system according to the carrier...

SIDE PORT CONNECTION

Factory preset O-ring with FPM - core FEP-FPM = [0 Subplate Piping Housing material: stainless steel Backlash (factory preset) Reduced tolerance = [1 Normal tolerance = [2 Increased tolerance = [3 Measuring range Size flow meter VHM Signal pick-up Combination VHM/AHM Housing material: Stainless steel Connection orientation Side connection = [ Bottom connection = Type of connection (other types on request) Standard Special Factory preset =□ GENERAL PRINCIPLE OF FUNCTIONING The two gear wheels of the instrument are set into motion by the volume flow passing through the flow meter. Each tooth of...

TYPE CODES – SIGNAL PICK-UP Cable gland Plug connector with VSE standard plug Size Flow meter 1 Flow meter 2 Flow meter 3 Standard Intrinsically safe Supply with lithium battery for fibre optic output 4-wire connection with U/I limiting 2-wire connection without U/I limiting Input: light impulses Output: electronic digital impulses Single-channel pick-up with modified carrier frequency Two-channel pick-up (impulses x 1) Two-channel pick-up* (impulses x 2 / impulse x 4) Single-channel pick-up with normal carrier frequency Converter (fibre optic receiver and converter) * For series VDB... (fibre...

SELECTION CRITERIA – SIGNAL PICK-UPS Single pick-ups series Vl ... / VT ... Double pick-ups series VD ... / VE ... General applications Flow velocity measurement and volume measurement Flow velocity measurement and volume measurement with high signal resolution Measured volume signal resolution per conveyed tooth gap volume a) 2 impulses / measured volume or 4 impulses / measured volume optionally coded by jumpers in the pick-up b) 1 impulse / measured volume in modified series VE ... Galvanic isolation between NPN- or PNP-switching optocoupler output the supply voltage and the signal output...

The single pick-up operates with a carrier frequency oscillator, which is modulated when a tooth passes. The double pick-up operates with two independent carrier frequency oscillators, which are modulated when a tooth passes. This modulation is detected by the amplifier and is used to generate a pulsing current signal in the supply current. The connected barrier amplifier detects the signal and generates a digital PNP signal for further processing. The output impulses per measured volume correspond to those of the two standard designs. Single pick-ups and double pick-ups in Ex-design are designed...

1 Explanation of series VT ... If detection of the direction of flow and high signal resolution with additional external circuitry is necessary, 2 single pick-ups are used in one flow meter body, which are arranged with a mechanical offset of 90° with regard to the tooth flank sequence

SIGNAL PICK-UPS FOR VHM FLOW METERS Technical data part 2 * Explanation for series VE... If a single pick-up (1 impulse per conveyed tooth gap volume) cannot be used in an application because of the length of its body (115 mm), a modified double pick-up of series VE... (body length 43 mm) can be used, which operates with only one active carrier frequency oscillator and delivers the signals as a single pick-up.

VHM type list single and double pick-ups Single pick-ups with not earthed 0 V-potential Single channel Singel channel pick-ups with pick-ups with normal carrier modified frequency carrier frequency Double pick-ups with not earthed 0 V-potential Double channel Double channel pick-ups with pick-ups (impulses x2/ impulses x4) modified   (impulses x1) 4-wire connection 4-wire connection with U / I-limiting with U / I-limiting 4-wire connection with U / I-limiting 4-wire connection with U / I-limiting 2-wire connection 2-wire connection with U / I-limiting with U / I-limiting 2-wire connection with...

SIGNAL PICK-UPS WITH OPTICAL FIBRE TECHNOLOGY FOR VHM FLOW METERS Technical data part 3 Dimensions 0 = 78 mm; height = 62 mm; overall height with sensor 72 mm Overall length with optical fibre and plug connector = 98 mm; L = 64 mm; B = 58 mm; H = 37 mm Mounting construction: 2 screws M4 or installation rail snap-in mounting DIN 50022 Protection type IP 54 IP 54 Material Anodised aluminium; coil holder in Aluminium stainless steel Associated fibre optic VUMI-O... Volume impulse / fault signal receiver Signal switching polarity: PNP or NPN programmable by 2 coding jumpers Installation site of the...

Number of signal outputs 1, includes information on the flow meter 2 volume impulses (flow meter) output impulses and status signals fault signals Signal resolution per 2 impulses (signal doubling) 2 impulses (signal doubling) conveyed tooth gap volume (measured volume Vm) Switching frequency f 3 Hz-1.0 kHz 3 Hz-1.0 kHz Volume impulses / Fibre optic output diode: One transistor each with series resistor fault signals- Digital optical signals to the fibre optic R = 1.2 k Q signal output circuit receiver (volume sensor signals; monitor signals in stand-by; battery status signals)

VHM - TYPE LIST OPTICAL FIBRE TECHNOLOGY PERFORMANCE CHARACTERISTICS OF THE FAULT SIGNAL OUTPUT If a low battery state is signalled, the green LED "Ready" extinguishes and the fault signal output becomes active, operation of the system remains possible for a certain time. The green LED "Ready" is switched on and the fault signal output is reset automatically when a new battery has been installed in the signal pick-up body. The fault signal output also becomes active on the following transmission errors of the optical fibre, by which the red LED "transmission error" also lights: A. Interruption...