Yokogawa Draft Pressure Transmitter

A common application for a Draft Pressure transmitters are in air handling systems.

Yokogawa uses their digital DPharp sensor to design a transmitter for this specific application.

EJA120E

Traditional-mount Differential Pressure Transmitter designed for Draft Range applications based on the EJA-E Series.

EJX120A

Traditional-mount Differential Pressure Transmitter designed for Draft Range applications based on the EJX-A Series.

Which Series Draft Pressure Transmitter is Right for You?

EJA120EEJX120A
EJA120EEJX120A
Accuracy
± 0.09%
± 0.1%
± 0.2%
Minimum Span
0.1 inH2O
0.4 inH2O
Response Time
150 msec
450 msec
Safety
FMEDA Report
IEC 61508 Certified (SIL 2)
Specification Conformance
±3σ

Draft Pressure Transmitter Introduction

Level transmitter configuration can be very time consuming. Calculations required to determine proper range values for traditional transmitters can become complex due to the physical layout of an application.

With maintenance shops getting smaller, finding equipment that allows us to do more with fens becomes a priority. DPharp transmitters with advanced software functionality can eliminate these complex calculations.

Draft Pressure Transmitter Application

Using typical smart or conventional products, all the following must be considered:

The specific gravity of the processSGP
Precise location of 0% and 100%

Specific Gravity of the capillary fill fluid
(or sealing fluid used in impulse piping)

SGFF
Exact orientation oi the transmitter to the vesselH2
Vertical distance between the process conn.H1

Depending on the application, the vessel may be open (referencing atmosphere) or closed (under a blanket pressure).

Elevation is typically used when the vessel is closed. To reference the blanket pressure, a low side remote seal may be used (or a wet leg). The capillary on remote seal creates a negative force on the transmitter equal to the vertical height times the specific gravity of the fill fluid.

Elevation = (H1 + H2) x SGFF

Suppression is a positive pressure created on the high-pressure side of the transmitter typically due to the transmitter being positioned below the 0% process connection. Suppression is present in both open arid closed vessels. Suppression is equal to the vertical distance between the 0% process connection and the transmitter times the Specific Gravity of the fill livid.

Suppression = H2 x SGFF

Span is the vertical distance between the process connections times the process medium’s Specific Gravity.

Span = H1 x SGP

Figure 1: Closed Tank
Figure 1: Closed Tank

Now that you have the ElevationSuppression, and Span, the calibration values can be calculated for the 0% (Empty) arid the 100% (Full).

Cal Value (0%) = Suppression – Elevation

Cal Value (100%) = (Suppression + Span) – Elevation

Example: (using figure 1)

SGP0.9H210 inches
SGFF0.8H120 inches

Cal Value 0%) = Suppression – Elevation
Cal Value (0%) = (H2 x SGFF) – (H1 + H2 x SGFF)
Cal Value (0%) = (10 x 0.8) – (20 + 10) x 0.8
Cal Value (0%) = 8 – 24
Cal Value 0%) = -16 inH2O

Cal Value (100%) = (Suppression + Span) – Elevation
Cal Value (100%) = ((H2 x SGFF) + (H1 x SGP)) – (H1 + H2) x SGFF
Cal Value (100%) = ((10 x 0.8) + (20 x 0.9)) – (20 + 10) x 0.8
Cal Value (100%) = (8 + 18) – 24
Cal Value (100%) = +2 inH2O

Therefore, Calibrated Range would be:

-16 inH2O +2 inH2O
0%100%
EmptyFull

Popular Products Series

SITRANS P DS3 SITRANS P DSIII

Siemens SITRANS DS-III pressure transmitter incorporates diagnostic capabilities, including high- or low-signal limit alarms, peak value registers that store maximum and minimum values for pressure, sensor temperature, and electronics temperature, and a dual-time programmable "watchdog" function that alerts you when pre-set maintenance and calibration times occur.

YOKOGAWA ZR402G Single Channel Oxygen Analyzer

The YOKOGAWA ZR402G converter is equipped with an LCD touch screen which has various setting displays, a calibration display, oxygen concentration trend display, with easier operation and improvement of display functions. The converter is equipped with various standard functions such as measurement and calculation as well as maintenance functions including self-test.

YOKOGAWA ZR22G DIRECT IN SITU ZIRCONIA OXYGEN ANALYZER

YOKOGAWA ZR22/ZR402G Single Channel Oxygen Analyzer

The ZR402G converter is equipped with an LCD touch screen which has various setting displays, a calibration display, oxygen concentration trend display, with easier operation and improvement of display functions. The converter is equipped with various standard functions such as measurement and calculation as well as maintenance functions including self-test. The ZR22G separate-type detector uses a high-reliability zirconia sensor, and its heater assembly can be replaced on site. The detector is mounted, for example, on the wall of a flue and can measure the gases directly. The ZR22S separate-type detector for explosion-proof applications is also available.

ROSEMOUNT 3300 GUIDED WAVE RADAR LEVEL TRANSMITTER

The Rosemount 3300 provides reliable and cost effective level measurements in most liquid storage and monitoring applications. Guided Wave Radar technology combined with advanced signal processing and sensitivity enables the Rosemount 3300 Series to deliver both level and interface measurement data from the same transmitter.

ROSEMOUNT 5300 SERIES – TEST and MEASUREMENT

EJA210A and EJA220A Flange Mounted Differential Pressure Transmitters

Yokogawa EJA120A Draft Range Differential Pressure Transmitter

Load more