Before getting into the differential pressure gauges, it’s essential to know the functionality of these gauges. There are four types of differential pressure gauges- Magnehelic, Photohelic, Minihelic and Digihelic gauge.
So, let’s know about the functionalities of these gauges, as we keep reading below:
- They measure and control positive as well as negative gas or room pressures.
- They provide a perfect way of monitoring and controlling the positive pressure differential suitable for a cleanroom.
- They enable you to meet ISO/FED STD 209E regarding a cleanroom pressure.
- They are also ideal for measuring differential pressure in a glovebox and the flow of air in an exhaust hood. Magnehelic principle guarantees wear-free accuracy within 2% of full scale.
- They resist shock and vibration.
- They are available in a number of pressure ranges to suit a wide range of applicationslike gauging an air filter,HVAC duct & room pressure measurement, monitoring an air conditioning system and measuring static air pressure and air vehicle.
To determine the positive pressure differentials between the cleanroom and adjacent areas, use Magnehelic gauges (range of 0.25 – 4.0” WC). Magnehelic gauges also measure the pressure drops across pre-filters and absolute filters. On the other hand, photohelic gauges can be used to exhaust air dampers for maintaining the room pressure within the prescribed limits. A control panel can be maintained for mounting all the gauges. Magnehelic gauges serve as the superior gauge in case of gauge calibration which is accomplished between room readings.
Now, let’s give you a brief on the different gauges individually. Read below:
Magnehelic Pressure Gauge
In the industry, a Magnehelic gauge is used to measure fan and blower pressures, air velocity, filter resistance, furnace draft, pressure drop across orifice plates, liquid levels with bubbler systems and fluidic systems. It also controls gas-air ratio and automatic valves. It also monitors blood and respiratory pressures in medical care equipment.
Photohelic Pressure Gauge
This model combines the Magnehelic gauge with a precise pressure switch that controls the high and low gas pressures. The knob controls and enables you to adjust the dual set points which allow for different deadband control. These set points contain photocells that activate DPDT relays when room pressure reaches beyond the limit. It can be set up to control corrective damper action. When the room pressure changes in an answer to damper motion, the indicator returns to the null band and the damper motion is stopped.
This gauge offers the latest designs for a dial type differential pressure gauge. It combines clean design, small in size, cost-friendly and ensures accuracy for the demanding applications. Over-pressure protection is built into the minihelic gauge by means of a blow-out casing folded in union with the diaphragm. The gauge will stand steady in case of rough exposure and also during high total pressure.
Digital Differential Pressure Gauge
This is a gauge which is a combination of digital display gauge, control relay switches and a transmitter with current output. For its unique combination, it’s a cost-effective instrument which is apt for measuring pressure, velocity and flow. It can achieve 0.5% full-scale accuracy making it the perfect controller for HVAC, glove boxes, hoods and clean rooms. It allows you to set a security code for any changes in user-set programming. Its menu driven keypad allows you to set pressure, response time, alarm setpoints and much more.