Krohne DK32 and DH34 Variable Area Flow Meters ... - Instrumart
Krohne DK32 and DH34 Variable Area Flow Meters ... - Instrumart
Krohne DK32 and DH34 Variable Area Flow Meters ... - Instrumart
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<strong>DK32</strong> - DK34 - DK37<br />
ELECTRICAL CONNECTIONS 4<br />
4.5.1 Power supply<br />
INFORMATION!<br />
The supply voltage has to be between 14.8VDC <strong>and</strong> 30VDC. This is based on the total resistance<br />
of the measuring loop. To determine this, add up the resistances of each component in the<br />
measuring loop (not including the meter).<br />
The required supply voltage can be calculated using the formula below:<br />
U ext. = R L * 22mA + 14.8V<br />
where<br />
U ext. = the minimum supply voltage <strong>and</strong><br />
R L = the total measuring loop resistance.<br />
INFORMATION!<br />
The power supply has to be able to supply a minimum of 22mA.<br />
4.5.2 Load for HART ® communication<br />
INFORMATION!<br />
For HART ® communication a load of at least 230 ohm is required.<br />
The maximum load impedance is calculated as follows:<br />
DANGER!<br />
Use a twisted two-core cable to prevent electrical interference from impeding the DC output<br />
signal.<br />
In some cases a shielded cable may be necessary. The cable shield may only be earthed<br />
(grounded) at one place (on the power supply unit).<br />
4.5.3 Parametrization<br />
The M8E electronic display can be parametrized via HART ® communications. DD (Device<br />
Descriptions) for AMS 6.x <strong>and</strong> PDM 5.2 <strong>and</strong> a DTM (Device Type Manager) are available for<br />
parametrization (download center).<br />
The current flowrate can be transmitted using the integral HART ® communications. A flow<br />
counter can be parametrized. Two limit values can be monitored. The limit values are assigned<br />
either to flow values or to the counter overflow. The limit values are not depicted on the display.<br />
01/2012 - 4000287103 MA <strong>DK32</strong>-34-37-R05-en<br />
www.krohne.com<br />
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