Manual EMA 160 Digital Manometer

halstrup wa cher halstrup-walcher GmbH Stegener Straße 10 D-79199 Kirchzarten Phone: [49] 07661 /39 63-0 Fax: [49] 07661 /39 63 99 e-mail: info@halstr...
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halstrup wa cher halstrup-walcher GmbH Stegener Straße 10 D-79199 Kirchzarten Phone: [49] 07661 /39 63-0 Fax: [49] 07661 /39 63 99 e-mail: [email protected] Internet: www.halstrup-walcher.de

Manual EMA 160 Digital Manometer

List of Contents 1. General Infomation 2. Method of Operation 3. Operating Elements 4. Commissioning the Device 5. Zero point adjustment 6. Connection 7. Changing between linear/square root law modes 8. Technical data:

halstrup-walcher GmbH, 79199 Kirchzarten

Manual EMA 160

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1.) General Information The EMA 160 battery-operated digital manometer is used to measure positive pressure, negative pressure and differential pressure in gases in the range from 200 Pa up to 20 kPa. Its robustness, ease of use and the (optional) analog output make it particularly suitable for customer service, servicing work and record keeping on heating, ventilation and air conditioning equipment. Automatic power-down prevents battery discharge if the device is accidentally not switched off. 2.) Method of Operation Pressure is measured by a load cell having a beryllium bronze membrane spring that is deflected between the two chambers of the load cell in accordance with the pressure difference. This deflection is converted to an electrical signal by a displacement measuring system. 3.) Operating Elements The device has three buttons: Left: ON / OFF Centre: Switch between linear/square root law Right: Zero point adjustment 2 mm sockets (Analog output)

4.)

Commissioning the Device

The device is switched on by pressing the "0/1" button once, and is then in the linear mode. The device is switched off by pressing the button again. If the symbol "BAT" appears in the display, the battery should be changed. The battery is accessible by removing the battery compartment cover on the rear of the device.

halstrup-walcher GmbH, 79199 Kirchzarten

Manual EMA 160

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If the device does not display a zero when the pressure connections are open, then proceeded as described under "5.) Zero Point Adjustment". The device is then ready to use. 5.) Zero point adjustment The device offers electronic zero point adjustment, and this should be carried out with open pressure connections before every measurement. In this way position errors and long-term drift of the zero point can be compensated. When the device is switched off the correction value is stored, and is available after switching on again. If the zero point has shifted since the last use, perhaps because the position has changed, the zero point should be adjusted once again. Errors resulting from the measuring cell having been overloaded cannot be compensated for by the electronics, and the zero point can no longer be set. In such a case the device must be returned to the manufacturer. 6.) Connection The EMA 160 is to be connected to the pressure to be measured using the positive pressure input (+) to measure positive pressure, the negative pressure input (-) to measure negative pressure, or using both inputs, observing the correct arithmetic sign, for the measurement of differential pressure. 7.) Changing between linear / square root law modes The "LIN / √ " button is used switch between the two modes. In the linear mode, the display of the device shows the pressure in directly proportional values. The same applies to the device's analog output. After changing to square root mode, a triangle is shown on the display. The result of the formula "1.291 * √ ∆p" is displayed; it corresponds directly to the flow rate in m/s if a Prandtl's Pitot tube is used. "∆p" refers here to the differential pressure at the device in Pa. The device's analog output is here proportional to the displayed figure. Measuring flow velocity: Example:

Device measuring range: Measured differential pressure: Display (according to square root law):

halstrup-walcher GmbH, 79199 Kirchzarten

Manual EMA 160

0...200 Pa 100.0 Pa 12.91 m / s

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Caution: The flow velocity displayed in corresponds to that of standard air with a density 1.2 kg / m3 (system pressure 1013 hPa, temperature 20 °C). If there are significant deviations from the standard values , then the displayed value must be corrected in accordance with the following equation: w = 1.291 * √ (1013 / B) * (T / 293) * (10000 / (100000 + Pstat)) *∆p where:

w...air speed in m / s B...barometric air pressure in hPa T...absolute temperature of the medium in K (273 + T (in °C)) Pstat...static pressure in Pa (system pressure) ∆p...differential pressure in Pa

Example:

Temperature of the medium: 65 °C, other conditions as standard, the static pressure is negligible Device measuring range: 0...200 Pa Measured differential pressure: 100.0 Pa according to the above formula: w = 1.291 * √ 1 * (338 / 293) * 1 * 100 m / s w = 13.86 m / s

Please bear in mind that reproducible measurements are not possible at low flow velocities. For this reason "trickle suppression" is active at the lower end of the measuring range in square root mode, so that both the display and the (optional) analog output are held at zero.

halstrup-walcher GmbH, 79199 Kirchzarten

Manual EMA 160

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8.)Technical data: Measuring ranges: 0...200 Pa (0.. 2 mbar) or 1.5... 18 m / s 0... 2 kPa (0... 20 mbar) or 5... 58 m / s 0... 20 kPa (0...200 mbar) or 15…180 m / s

(overload capacity factor 20) (overload capacity factor 20) (overload capacity factor 10)

Other measurement units on request. Media:

Air or any non-corrosive gas

Pressure connection:

ø 6.5 mm for hose with nominal diameter 5

Analog output:

0... 2 Volt for 0 to full scale value, socket ø 2 mm, RL ≥ 10 kΩ

Display:

Liquid-crystal, 3½-characters, number height 13 mm

Linearity:

± 1% ± 1 digit with reference to the full-scale value

Amplitude drift / temperature

± ± 0.04 % / K (in the range from +10...+50 °C)

Square root extraction conformity:

± 2.5 %

Trickle suppression range:

at approximately 2.5 % of the linear measuring

Amplitude drift / temperature of the root extraction:

± 0.1 % / K (in the range from +10...+50 °C)

Hysteresis:

± 0.1 %

Dimensions:

80 x 34.5 x 148 mm (W x D x L)

Weight:

approx. 300 g inc. battery

Storage temperature:

- 10... + 70 °C

Operating temperature

0... 60 °C

Battery type:

9V - one-piece battery (IEC 6 LR 61)

Battery life:

approx. 120 hours continuous operation

22.05.01 Su/km

EMA_160_Manual.DOC

halstrup-walcher GmbH, 79199 Kirchzarten

7100.003104 REV A

Manual EMA 160

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