|Place of Origin:||UK|
|Minimum Order Quantity:||10 pcs|
|Delivery Time:||4-5 weeks|
|Payment Terms:||T/T payment|
|Supply Ability:||300 pcs|
MTL4544B (MTL4044 replacement) provides fully-floating dc supplies for energising two conventional 2- or 3-wire 4/20mA or HART transmitters located in a hazardous area, and repeats the current in other circuits to drive two safe-area loads. For HART transmitters, the unit allows bi-directional transmission of digital communication signals superimposed on the 4/20mA signal so that the transmitter can be interrogated either from the operator station or by a hand-held communicator.
See also common specification
Number of channels
Location of transmitter
Zone 0, IIC, T4-6, hazardous area if suitably certified
Div 1, Group A, hazardous location
Signal range: 4 to 20mA
Under/over-range: 0 to 24mA
Safe-area load resistance: 0 to 360Ω @ 24mA
0 to 450Ω @ 20mA
Safe-area circuit output resistance: > 1MΩ
Safe-area circuit ripple
< 50μA peak-to-peak
Signal range: 0 to 24mA (including over-range)
Transmitter voltage: 16.5V at 20mA
Transfer accuracy at 20°C
Better than 20μA
Settles to within 10% of final value within 50μs
HART® (terminals 1 & 2 and 4 & 5 only)
Note: Safe area output referenced to PSU –ve
Green: power indication
Maximum current consumption (with 20mA signals)
96mA at 24V dc
Power dissipation within unit (with 20mA signals)
1.4W at 24V dc
Safety description (each channel)
Terminals 2 to 1 and 3, and 5 to 4 and 6:
Vo=28V Io=93mA Po=651mW Um = 253V rms or dc
Terminals 1 to 3 and 4 to 6:
Simple apparatus ≤1.5V, ≤0.1A and ≤25mW; can be connected
without further certification into any IS loop with an open-circuit
Functional Safety Management (FSM)
Many MTL products are certified as safe for use in hazardous areas; that is places where explosive material may be present. The products are designed and certified to show that they are incapable of igniting the gas or dust and causing fire or explosion.
Another type of safety is called Functional Safety, which applies when products are used in safety and protection systems, in which a failure may mean that a protective system will not operate as it should. MTL products have been used in safety systems for some time, but there are increasing requirements to demonstrate an adequate level of functional safety, especially after the Buncefield, Texas City and Deepwater Horizon accidents. More and more, customers are demanding that products they use in safety systems meet the requirements of the second edition of the IEC 61508 Functional Safety standard, and they require evidence to show that they do. This is to enable the use of our products within instrumentation loops that are designed to achieve a specific Safety Integrity Level (SIL).
When MTL designs a product in the expectation that it will be used in functional safety-related systems, both the design process and the product needs to comply with IEC 61508:2010.
MTL has chosen to obtain Functional Safety Management (FSM) certification for the company. FSM means that MTL has the necessary processes and competence to design products according to IEC 61508:2010. Certification means that a notified body is ensuring that our processes are correct and that we are working to them. Together, FSM Certification gives our customers confidence in the company and the use of our products for functional safety.